The Experts below are selected from a list of 783 Experts worldwide ranked by ideXlab platform

Yonghua Wang - One of the best experts on this subject based on the ideXlab platform.

  • Malassezia globosa MgMDL2 lipase: Crystal structure and rational modification of substrate specificity
    Biochemical and biophysical research communications, 2017
    Co-Authors: Dongming Lan, Grzegorz Dubin, Jinsong Liu, Faez Iqbal Khan, Yonghua Wang
    Abstract:

    Lipases play an important role in physiological metabolism and diseases, and also have multiple industrial applications. Rational modification of lipase specificity may increase the commercial utility of this group of enzymes, but is hindered by insufficient mechanistic understanding. Here, we report the 2.0 A resolution crystal structure of a mono- and di-acylglycerols lipase from Malassezia globosa (MgMDL2). Interestingly, residues Phe278 and Glu282 were found to involve in substrate recognition because mutation on each residue led to convert MgMDL2 to a triacylglycerol (TAG) lipase. The Phe278Ala and Glu282Ala mutants also acquired ability to synthesize TAGs by esterification of glycerol and fatty acids. By in silicon analysis, steric hindrance of these residues seemed to be key factors for the altered substrate specificity. Our work may shed light on understanding the unique substrate selectivity mechanism of mono- and di-acylglycerols lipases, and provide a new insight for engineering biocatalysts with desired catalytic behaviors for biotechnological application.

  • diacylglycerol production by genetically modified lipase from Malassezia globosa
    Journal of Molecular Catalysis B-enzymatic, 2016
    Co-Authors: Daoming Li, Faez Iqbal Khan, Zexin Zhao, Weifei Wang, Bo Yang, Yonghua Wang
    Abstract:

    Abstract Diacylglycerol (DAG)-enriched oil has drawn considerable attention for the prevention of obesity and other lifestyle-related diseases. In this study, a mutant lipase of SMG1 (SMG1-F278D) from Malassezia globosa was studied for the production of DAG. The SMG1-F278D exhibited 4-fold increased esterification activity as well as superior fatty acid (FA) specificity for medium chain FAs. Molecular docking study suggested that the caprylic acid (CA) was strongly bound to the catalytic residue Ser171 present in the SMG1-F278D as compared to SMG1. Molecular Dynamics (MD) simulations were employed in order to understand the structural conformations of SMG1 and SMG1-F278D. The structure of SMG1-F278D was found to be more compact as well as less deviated from its native conformation. There was an increase in β-sheet as well as α-helix in the SMG1-F278D that may stabilize the protein structure due to point mutation. Finally, the capability of SMG1-F278D in synthesis of DAG was evaluated. Effects of reaction parameters such as substrate molar ratio of glycerol to FAs, enzyme loading and reaction temperature on the esterification were investigated. The optimal reaction conditions were achieved as 4:1 molar ratio of glycerol to FAs, enzyme loading of 100 U/g (U/w, with respect to the total substrates) and temperature of 25 °C. The present study provides important information about SMG1 mutant for better utilization in the oils and fats industries.

  • Lid mobility in lipase SMG1 validated using a thiol/disulfide redox potential probe.
    FEBS open bio, 2016
    Co-Authors: Shaohua Guo, Grzegorz Maria Popowicz, Dongjuan Yuan, Yonghua Wang
    Abstract:

    Most lipases possess a lid domain above the catalytic site that is responsible for their activation. Lipase SMG1 from Malassezia globose CBS 7966 (Malassezia globosa LIP1), is a mono- and diacylglycerol lipase with an atypical loop-like lid domain. Activation of SMG1 was proposed to be solely through a gating mechanism involving two residues (F278 and N102). However, through disulfide bond cross-linking of the lid, this study shows that full activation also requires mobility of the lid domain, contrary to a previous proposal. The newly introduced disulfide bond makes lipase SMG1 eligible as a ratiometric thiol/disulfide redox potential probe, when it is coupled with chromogenic substrates. This redox-switch lipase could also be of potential use in cascade biocatalysis.

  • The Role of Residues 103, 104, and 278 in the Activity of SMG1 Lipase from Malassezia globosa: A Site-Directed Mutagenesis Study.
    Journal of microbiology and biotechnology, 2015
    Co-Authors: Dongming Lan, Grzegorz M Popowicz, Bo Yang, Qian Wang, Qingyun Tang, Yonghua Wang
    Abstract:

    The SMG1 lipase from Malassezia globosa is a newly found mono- and diacylglycerol (DAG) lipase that has a unique lid in the loop conformation that differs from the common alpha-helix lid. In the present study, we characterized the contribution of three residues, L103 and F104 in the lid and F278 in the rim of the binding site groove, on the function of SMG1 lipase. Sitedirected mutagenesis was conducted at these sites, and each of the mutants was expressed in the yeast Pichia pastoris, purified, and characterized for their activity toward DAG and pnitrophenol (pNP) ester. Compared with wild-type SMG1, F278A retained approximately 78% of its activity toward DAG, but only 11% activity toward pNP octanoate (pNP-C8). L103G increased its activity on pNP-C8 by approximately 2-fold, whereas F104G showed an approximate 40% decrease in pNP-C8 activity, and they both showed decreased activity on the DAG emulsion. The deletion of 103-104 retained approximately 30% of its activity toward the DAG emulsion, with an almost complete loss of pNP-C8 activity. The deletion of 103-104 showed a weaker penetration ability to a soybean phosphocholine monolayer than wild-type SMG1. Based on the modulation of the specificity and activity observed, a pNP-C8 binding model for the ester (pNP-C8, N102, and F278 form a flexible bridge) and a specific lipidanchoring mechanism for DAG (L103 and F104 serve as "anchors" to the lipid interface) were proposed.

  • novel inhibitor against Malassezia globosa lip1 smg1 a potential anti dandruff target
    Bioorganic & Medicinal Chemistry Letters, 2015
    Co-Authors: Shaohua Guo, Wenkang Huang, Jian Zhang, Yonghua Wang
    Abstract:

    Compelling evidence have demonstrated the role of lipase activity in the pathogenicity of Malassezia globosa toward dandruff and seborrheic dermatitis (D/SD). As a representative secreted lipase from M. globosa CBS 7966, Malassezia globosa LIP1 (SMG1) is considered a potential anti-dandruff target. In this study, homology modeling, docking-based virtual screening and in vitro lipase-based assay were integrated to identify the first hit compound against SMG1, with an IC50 of 20 μM against synthetic lipase substrate, and of 0.19 μM when using natural lipase substrate. Evaluation of similar compounds, along with docking, offered information on the binding patterns of the hit compound. This work is expected to serve as a starting point for the rational design of more potent inhibitors against SMG1.

Thomas L. Dawson - One of the best experts on this subject based on the ideXlab platform.

  • Effect of zinc pyrithione shampoo treatment on skin commensal Malassezia.
    Medical mycology, 2020
    Co-Authors: Cheryl Leong, Joyce Wang, Min Jet Toi, Yuen In Lam, Joleen P. Z. Goh, Shi Mun Lee, Thomas L. Dawson
    Abstract:

    Malassezia restricta and Malassezia globosa are lipid dependent commensal yeasts associated with dandruff. Antifungal actives such as zinc pyrithione are commonly used in antidandruff shampoos, although their efficacy is not clearly demonstrated. In this study, we assessed the efficacy of antifungal treatments on scalp Malassezia via a combination of culturomic and genomic detection methods. Zinc pyrithione inhibited Malassezia growth at low minimum inhibitory concentrations (MICs). In a longitudinal pilot study, quantitative polymerase chain reaction (qPCR) analysis showed a decrease in M. restricta on the scalp after zinc pyrithione treatment. These findings validate the antifungal efficacy of zinc pyrithione as a dandruff treatment.

  • skin commensal Malassezia globosa secreted protease attenuates staphylococcus aureus biofilm formation
    Journal of Investigative Dermatology, 2017
    Co-Authors: Hao Li, Thomas L. Dawson, Zhenze Jiang, Guangxi Wu, Shawn Hoon, Manfred Raida, Andrea Camattari, Liang Yang, Anthony J Odonoghue
    Abstract:

    Skin provides the first defense against pathogenic micro-organisms and is also colonized by a diverse microbiota. Phylogenetic analysis of whole skin microbiome at different skin sites in health and disease has generated important insights on possible microbial involvement in modulating skin health. However, functional roles of the skin microbial community remain unclear. The most common sebaceous skin commensal yeasts are the basidiomycetes, Malassezia . Here, we characterized the dominant secreted Malassezia globosa protease in culture and subsequently named it Malassezia globosa Secreted Aspartyl Protease 1 (MgSAP1). We defined recombinant MgSAP1's substrate cleavage profile using an unbiased, mass-spectrometry−based technique. We show that this enzyme is physiologically relevant as mgsap1 expression was detected on at least one facial skin site of 17 healthy human volunteers. In addition, we demonstrated that this protease rapidly hydrolyzes Staphylococcus aureus protein A, an important S. aureus virulence factor involved in immune evasion and biofilm formation. We further observed that MgSAP1 has anti-biofilm properties against S. aureus . Taken together, our study defines a role for the skin fungus Malassezia in inter-kingdom interactions and suggests that this fungus and the enzymes it produces may be beneficial for skin health.

  • Malassezia globosa and restricta breakthrough understanding of the etiology and treatment of dandruff and seborrheic dermatitis through whole genome analysis
    Journal of Investigative Dermatology Symposium Proceedings, 2007
    Co-Authors: Thomas L. Dawson
    Abstract:

    Dandruff and seborrheic dermatitis (D/SD) share an etiology dependent upon three factors: sebum, microbial metabolism (specifically, Malassezia yeasts), and individual susceptibility. Advances in microbiological and analytical techniques permit a more detailed understanding of these etiologic factors, especially the role of Malassezia . Malassezia are lipid-dependent and demonstrate adaptation allowing them to exploit a narrow niche on sebum-rich skin. Work in our and our collaborators' laboratories has focused on understanding these adaptations by detailed analysis of biochemistry and gene expression. We have shown that Malassezia globosa and M. restricta predominate on dandruff scalp, that oleic acid alone can initiate dandruff-like desquamation, that M. globosa is the most likely initiating organism by virtue of its high lipase activity, and that an M. globosa lipase is expressed on human scalp. Considering the importance of M. globosa in D/SD (and the overall importance of commensal fungi), we have sequenced the M. globos a and M. restricta genomes. Genomic analysis indicates key adaptations to the skin environment, several of which yield important clues to the role Malassezia play in human disease. This work offers the promise of defining new treatments to D/SD that are targeted at changing the level or activities of Malassezia genes.

Claudiu T. Supuran - One of the best experts on this subject based on the ideXlab platform.

  • Sulfonamide Inhibition Profile of the β-Carbonic Anhydrase from Malassezia restricta, An Opportunistic Pathogen Triggering Scalp Conditions.
    Metabolites, 2020
    Co-Authors: Sonia Del Prete, Claudiu T. Supuran, Cécile Clavaud, Andrea Angeli, Cynthia Ghobril, Julien Hitce, Xavier Marat, Clemente Capasso
    Abstract:

    The critical CO2 hydration reaction to bicarbonate and protons is catalyzed by carbonic anhydrases (CAs, EC 4.2.1.1). Their physiological role is to assist the transport of the CO2 and HCO3- at the cellular level, which will not be ensured by the low velocity of the uncatalyzed reaction. CA inhibition may impair the growth of microorganisms. In the yeasts, Candida albicans and Malassezia globosa, the activity of the unique β-CA identified in their genomes was demonstrated to be essential for growth of the pathogen. Here, we decided to investigate the sulfonamide inhibition profile of the homologous β-CA (MreCA) identified in the genome of Malassezia restricta, an opportunistic pathogen triggering dandruff and seborrheic dermatitis. Among 40 investigated derivatives, the best MreCA sulfonamide inhibitors were dorzolamide, brinzolamide, indisulam, valdecoxib, sulthiam, and acetazolamide (KI < 1.0 μM). The MreCA inhibition profile was different from those of the homologous enzyme from Malassezia globosa (MgCA) and the human isoenzymes (hCA I and hCA II). These results might be useful to for designing CA inhibitor scaffolds that may selectively inhibit the dandruff-producing fungi.

  • Benzamide-4-Sulfonamides Are Effective Human Carbonic Anhydrase I, II, VII, and IX Inhibitors.
    Metabolites, 2018
    Co-Authors: Morteza Abdoli, Andrea Angeli, Murat Bozdag, Claudiu T. Supuran
    Abstract:

    A series of benzamides incorporating 4-sulfamoyl moieties were obtained by reacting 4-sulfamoyl benzoic acid with primary and secondary amines and amino acids. These sulfonamides were investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The human (h) isoforms hCA II, VII, and IX were inhibited in the low nanomolar or subnanomolar ranges, whereas hCA I was slightly less sensitive to inhibition (KIs of 5.3⁻334 nM). The β- and γ-class CAs from pathogenic bacteria and fungi, such as Vibrio cholerae and Malassezia globosa, were inhibited in the micromolar range by the sulfonamides reported in the paper. The benzamide-4-sulfonamides are a promising class of highly effective CA inhibitors.

  • natural polyphenols selectively inhibit β carbonic anhydrase from the dandruff producing fungus Malassezia globosa activity and modeling studies
    ChemMedChem, 2018
    Co-Authors: Alessio Nocentini, Yeganeh Entezari Heravi, Sonia Del Prete, Ali Akbar Saboury, Clemente Capasso, Paola Gratteri, Anastasia Karioti, Anna Rita Bilia, Claudiu T. Supuran
    Abstract:

    : Around 50 % of the worldwide population is affected by dandruff, which is triggered by a variety of factors. The yeast Malassezia globosa has been labeled as the most probable causative agent for the onset of dandruff. The β-carbonic anhydrase (CA) of MgCA was recently validated as an anti-dandruff target, with its inhibition being responsible for in vivo growth defects in the fungus. As classical CA inhibitors of the sulfonamide type give rise to permeability problems through biological membranes, finding non-sulfonamide alternatives for MgCA inhibition is of considerable interest in the cosmetic field. We recently screened a large library of human (h) CA inhibitors for MgCA inhibition, including different chemotypes, such as monothiocarbamates, dithiocarbamates, phenols, and benzoxaboroles. Herein, we expanded the research toward new MgCA inhibitors by considering a set of natural polyphenols (including flavones, flavonols, flavanones, flavanols, isoflavones, and depsides) that exhibited MgCA inhibitory activity in the micromolar range, as well as selectivity for the fungal isozyme over off-target human isoforms. The binding mode of representative derivatives within the MgCA catalytic cleft was investigated by docking studies using a homology-built model.

  • Benzamide-4-Sulfonamides Are Effective Human Carbonic Anhydrase I, II, VII, and IX Inhibitors
    MDPI AG, 2018
    Co-Authors: Morteza Abdoli, Andrea Angeli, Murat Bozdag, Claudiu T. Supuran
    Abstract:

    A series of benzamides incorporating 4-sulfamoyl moieties were obtained by reacting 4-sulfamoyl benzoic acid with primary and secondary amines and amino acids. These sulfonamides were investigated as inhibitors of the metalloenzyme carbonic anhydrase (CA, EC 4.2.1.1). The human (h) isoforms hCA II, VII, and IX were inhibited in the low nanomolar or subnanomolar ranges, whereas hCA I was slightly less sensitive to inhibition (KIs of 5.3–334 nM). The β- and γ-class CAs from pathogenic bacteria and fungi, such as Vibrio cholerae and Malassezia globosa, were inhibited in the micromolar range by the sulfonamides reported in the paper. The benzamide-4-sulfonamides are a promising class of highly effective CA inhibitors

  • Benzoxaboroles as Efficient Inhibitors of the β-Carbonic Anhydrases from Pathogenic Fungi: Activity and Modeling Study.
    ACS medicinal chemistry letters, 2017
    Co-Authors: Alessio Nocentini, Claudiu T. Supuran, Clemente Capasso, Paola Gratteri, Sonia Del Prete, Roberta Cadoni, Pascal Dumy, Jean-yves Winum
    Abstract:

    A series of 6-substituted benzoxaboroles were investigated as inhibitors of the β-class carbonic anhydrase from three pathogenic fungi (Cryptococcus neoformans, Candida glabrata, and Malassezia globosa). Independently from the nature of the substituents on the phenyl of the urea/thiourea group, all reported derivatives showed nanomolar inhibitory activities against Can2 and CgNce103 vs micromolar inhibition against MgCA. Selectivity over human CA I and CA II was noticed. The observed structure–activity relationship trends have been rationalized by modeling study of selected compounds into the active site of Can2 and MgCA. The present letter demonstrates that benzoxaborole chemotype may offer interesting opportunities for the inhibition of β-CA from pathogenic fungi and for the development of antifungal agents with a new mechanism of action.

Bo Yang - One of the best experts on this subject based on the ideXlab platform.

  • diacylglycerol production by genetically modified lipase from Malassezia globosa
    Journal of Molecular Catalysis B-enzymatic, 2016
    Co-Authors: Daoming Li, Faez Iqbal Khan, Zexin Zhao, Weifei Wang, Bo Yang, Yonghua Wang
    Abstract:

    Abstract Diacylglycerol (DAG)-enriched oil has drawn considerable attention for the prevention of obesity and other lifestyle-related diseases. In this study, a mutant lipase of SMG1 (SMG1-F278D) from Malassezia globosa was studied for the production of DAG. The SMG1-F278D exhibited 4-fold increased esterification activity as well as superior fatty acid (FA) specificity for medium chain FAs. Molecular docking study suggested that the caprylic acid (CA) was strongly bound to the catalytic residue Ser171 present in the SMG1-F278D as compared to SMG1. Molecular Dynamics (MD) simulations were employed in order to understand the structural conformations of SMG1 and SMG1-F278D. The structure of SMG1-F278D was found to be more compact as well as less deviated from its native conformation. There was an increase in β-sheet as well as α-helix in the SMG1-F278D that may stabilize the protein structure due to point mutation. Finally, the capability of SMG1-F278D in synthesis of DAG was evaluated. Effects of reaction parameters such as substrate molar ratio of glycerol to FAs, enzyme loading and reaction temperature on the esterification were investigated. The optimal reaction conditions were achieved as 4:1 molar ratio of glycerol to FAs, enzyme loading of 100 U/g (U/w, with respect to the total substrates) and temperature of 25 °C. The present study provides important information about SMG1 mutant for better utilization in the oils and fats industries.

  • The Role of Residues 103, 104, and 278 in the Activity of SMG1 Lipase from Malassezia globosa: A Site-Directed Mutagenesis Study.
    Journal of microbiology and biotechnology, 2015
    Co-Authors: Dongming Lan, Grzegorz M Popowicz, Bo Yang, Qian Wang, Qingyun Tang, Yonghua Wang
    Abstract:

    The SMG1 lipase from Malassezia globosa is a newly found mono- and diacylglycerol (DAG) lipase that has a unique lid in the loop conformation that differs from the common alpha-helix lid. In the present study, we characterized the contribution of three residues, L103 and F104 in the lid and F278 in the rim of the binding site groove, on the function of SMG1 lipase. Sitedirected mutagenesis was conducted at these sites, and each of the mutants was expressed in the yeast Pichia pastoris, purified, and characterized for their activity toward DAG and pnitrophenol (pNP) ester. Compared with wild-type SMG1, F278A retained approximately 78% of its activity toward DAG, but only 11% activity toward pNP octanoate (pNP-C8). L103G increased its activity on pNP-C8 by approximately 2-fold, whereas F104G showed an approximate 40% decrease in pNP-C8 activity, and they both showed decreased activity on the DAG emulsion. The deletion of 103-104 retained approximately 30% of its activity toward the DAG emulsion, with an almost complete loss of pNP-C8 activity. The deletion of 103-104 showed a weaker penetration ability to a soybean phosphocholine monolayer than wild-type SMG1. Based on the modulation of the specificity and activity observed, a pNP-C8 binding model for the ester (pNP-C8, N102, and F278 form a flexible bridge) and a specific lipidanchoring mechanism for DAG (L103 and F104 serve as "anchors" to the lipid interface) were proposed.

  • Hydrolysis of lysophosphatidylcholines by a lipase from Malassezia globosa
    European Journal of Lipid Science and Technology, 2015
    Co-Authors: Xuping Wang, Bo Yang, Dongming Lan, Yonghua Wang
    Abstract:

    SMG1, a lipase produced by recombinant Pichia pastoris shows specific activity on mono- and diacylglycerol but not on triacylglycerol. To better understand the substrate selectivity of SMG1, the hydrolysis ability of SMG1 on PC and LPC were investigated. SMG1 was found to hydrolyze LPC, but has no activity toward PC. Besides, SMG1 lipase preferred 2-LPC to 1-LPC. Molecular docking simulation indicated that Phe278 and Leu103 contribute to reduce the size of the catalytic pocket, resulting in preventing PC access to the active site of SMG1. Our work may shed some light to understand the molecular basis of substrate selectivity of lipase with preference for DAGs. Practical applications: To our knowledge, there is no report on the application of lipases with preference for DAGs in phospholipids modification. This study could contribute to develop potential applications of SMG1 lipase in phospholipids industries. (A) Hydrolysis curve of 1-LPC, 2-LPC, and PC by SMG1 (B) Modeled 3-D structure of the SMG1-2-LPC complex (C) Modeled 3-D structure of the SMG1-1-LPC complex (D) F278 prevents PC enter into catalytic pocket.

  • Residue Asn277 Affects the Stability and Substrate Specificity of the SMG1 Lipase from Malassezia globosa
    International journal of molecular sciences, 2015
    Co-Authors: Dongming Lan, Pengfei Zhou, Bo Yang, Qian Wang, Yonghua Wang
    Abstract:

    Thermostability and substrate specificity are important characteristics of enzymes for industrial application, which can be improved by protein engineering. SMG1 lipase from Malassezia globosa is a mono- and diacylglycerol lipase (MDL) that shows activity toward mono- and diacylglycerols, but no activity toward triacylglycerols. SMG1 lipase is considered a potential biocatalyst applied in oil/fat modification and its crystal structure revealed that an interesting residue-Asn277 may contribute to stabilize loop 273–278 and the 3104 helix which are important to enzyme characterization. In this study, to explore its role in affecting the stability and catalytic activity, mutagenesis of N277 with Asp (D), Val (V), Leu (L) and Phe (F) was conducted. Circular dichroism (CD) spectral analysis and half-life measurement showed that the N277D mutant has better thermostability. The melting temperature and half-life of the N277D mutant were 56.6 °C and 187 min, respectively, while that was 54.6 °C and 121 min for SMG1 wild type (WT). Biochemical characterization of SMG1 mutants were carried out to test whether catalytic properties were affected by mutagenesis. N277D had similar enzymatic properties as SMG1 WT, but N277F showed a different substrate selectivity profile as compared to other SMG1 mutants. Analysis of the SMG1 3D model suggested that N277D formed a salt bridge via its negative charged carboxyl group with a positively charged guanidino group of R227, which might contribute to confer N277D higher temperature stability. These findings not only provide some clues to understand the molecular basis of the lipase structure/function relationship but also lay the framework for engineering suitable MDL lipases for industrial applications.

  • A mechanistic study into the epoxidation of carboxylic acid and alkene in a mono, di-acylglycerol lipase
    Biochemical and biophysical research communications, 2015
    Co-Authors: Xuping Wang, Grzegorz M Popowicz, Bo Yang, Qingyun Tang, Yonghua Wang
    Abstract:

    Abstract More and more industrial chemistry reactions rely on green technologies. Enzymes are finding increasing use in diverse chemical processes. Epoxidized vegetable oils have recently found applications as plasticizers and additives for PVC production. We report here an unusual activity of the Malassezia globosa lipase (SMG1) that is able to catalyze epoxidation of alkenes. SMG1 catalyzes formation of peroxides from long chain carboxylic acids that subsequently react with double bonds of alkenes to produce epoxides. The SMG1 is selective towards carboxylic acids and active also as a mutant lacking hydrolase activity. Moreover we present previously unobserved mechanism of catalysis that does not rely on acyl–substrate complex nor tetrahedral intermediate. Since SMG1 lipase is activated by allosteric change upon binding to the lipophilic–hydrophilic phase interface we reason that it can be used to drive the epoxidation in the lipophilic phase exclusively.

Takashi Sugita - One of the best experts on this subject based on the ideXlab platform.

  • Low DNA Sequence Diversity of the Intergenic Spacer 1 Region in the Human Skin Commensal Fungi Malassezia sympodialis and M. dermatis Isolated from Patients with Malassezia-Associated Skin Diseases and Healthy Subjects
    Mycopathologia, 2016
    Co-Authors: Otomi Cho, Takashi Sugita
    Abstract:

    As DNA sequences of the intergenic spacer (IGS) region in the rRNA gene show remarkable intraspecies diversity compared with the small subunit, large subunit, and internal transcribed spacer region, the IGS region has been used as an epidemiological tool in studies on Malassezia globosa and M . restricta , which are responsible for the exacerbation of atopic dermatitis (AD) and seborrheic dermatitis (SD). However, the IGS regions of M . sympodialis and M . dermatis obtained from the skin of patients with AD and SD, as well as healthy subjects, lacked sequence diversity. Of the 105 M . sympodialis strains and the 40 M . dermatis strains, the sequences of 103 (98.1 %) and 39 (97.5 %), respectively, were identical. Thus, given the lack of intraspecies diversity in the IGS regions of M . sympodialis and M . dermatis , studies of the diversity of these species should be performed using appropriate genes and not the IGS.

  • genotype analyses of human commensal scalp fungi Malassezia globosa and Malassezia restricta on the scalps of patients with dandruff and healthy subjects
    Mycopathologia, 2014
    Co-Authors: Takashi Sugita, M Hiruma, Otomi Cho, Sanae Kurakado, Shigaku Ikeda
    Abstract:

    Dandruff and seborrheic dermatitis are common afflictions of the human scalp caused by commensal scalp fungi belonging to the genus Malassezia. Malassezia globosa and Malassezia restricta are the predominant species found on the scalp. The intergenic spacer regions of these species' rRNA genes contain short sequence repeats (SSR): (GT)n and (CT)n in M. globosa and (CT)n and (AT)n in M. restricta. In the present study, we compared the genotypes (SSR) of M. globosa and M. restricta colonizing the scalps of patients with dandruff and healthy individuals. For M. globosa, the genotype (GT)10:(CT)8 (40.3 %, 25/62) was predominant followed by (GT)9:(CT)8 (14.5 %, 9/62) and (GT)11:(CT)8 (14.5 %, 9/62) in patients with dandruff, whereas the genotypes in healthy subjects were diverse. For M. restricta, the genotype (CT)6:(AT)6 (59.7 %, 37/62) was predominant followed by (CT)6:(AT)8 (24.2 %, 15/62) in patients with dandruff, while four genotypes, (CT)6:(AT)6 (10.5 %, 6/57), (CT)6:(AT)7 (22.8 %, 13/57), (CT)6:(AT)8 (17.5 %, 10/57), and (CT)6:(AT)10 (21.1 %, 12/57), accounted for 71.9 % of all combinations in healthy subjects. The results of this study suggest that the M. globosa genotype (GT)10:(CT)8 and the M. restricta genotype (CT)6:(AT)6 may be involved in the development of dandruff.

  • Molecular epidemiology of Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor.
    Mycopathologia, 2013
    Co-Authors: M. Saad, H. Saeed, Takashi Sugita, A Ahmed
    Abstract:

    Pityriasis versicolor is a superficial infection of the stratum corneum caused by Malassezia yeasts. The cutaneous Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor were elucidated using a molecular-based, culture-independent method and compared with that in healthy individuals. Scale samples were collected by applying an Opsite™ transparent dressing to lesional and non-lesional sites on 29 Sudanese patients with pityriasis versicolor and 54 healthy individuals. Malassezia DNA was extracted directly from the samples. The overall level of colonization by Malassezia globosa and Malassezia restricta was analyzed by real-time PCR using a TaqMan probe. The overall level of colonization by Malassezia at the lesional sites was higher than that at the non-lesional sites for all body sites, including the face, neck, cheeks, and trunk (2.7- to 6.0-fold increase). Both M. globosa and M. restricta were detected in patients and healthy individuals. However, M. globosa predominated at lesional sites, whereas the level of colonization by both species was similar in healthy individuals.

  • Molecular Epidemiology of Malassezia globosa and Malassezia restricta in Sudanese Patients with Pityriasis Versicolor
    Mycopathologia, 2013
    Co-Authors: M. Saad, H. Saeed, Takashi Sugita, A Ahmed
    Abstract:

    Pityriasis versicolor is a superficial infection of the stratum corneum caused by Malassezia yeasts. The cutaneous Malassezia globosa and Malassezia restricta in Sudanese patients with pityriasis versicolor were elucidated using a molecular-based, culture-independent method and compared with that in healthy individuals. Scale samples were collected by applying an Opsite™ transparent dressing to lesional and non-lesional sites on 29 Sudanese patients with pityriasis versicolor and 54 healthy individuals. Malassezia DNA was extracted directly from the samples. The overall level of colonization by Malassezia globosa and Malassezia restricta was analyzed by real-time PCR using a TaqMan probe. The overall level of colonization by Malassezia at the lesional sites was higher than that at the non-lesional sites for all body sites, including the face, neck, cheeks, and trunk (2.7- to 6.0-fold increase). Both M. globosa and M. restricta were detected in patients and healthy individuals. However, M. globosa predominated at lesional sites, whereas the level of colonization by both species was similar in healthy individuals.

  • Identification of the major allergen of Malassezia globosa relevant for atopic dermatitis.
    Journal of dermatological science, 2009
    Co-Authors: Yoshio Ishibashi, Takashi Sugita, Hiroshi Kato, Yoko Asahi, Akemi Nishikawa
    Abstract:

    Abstract Background Malassezia globosa constitutes a part of the normal flora of human skin, but may induce IgE production in atopic dermatitis (AD). However, information on M. globosa allergens is scant. Objective To identify the major M. globosa allergens by using proteomic analysis. Methods Immunoglobulin E (IgE) immunoblotting and cross-inhibition tests for M. globosa allergens were performed using sera from AD patients and control subjects. These allergens were identified and characterized using the proteomics approach involving a combination of two-dimensional (2D) electrophoresis, mass spectrometry, and bioinformatics tools. We cloned the cDNA of this allergen using sequences obtained by 5′- and 3′-rapid amplification of cDNA ends polymerase chain reaction. Results The sera of the AD patients had IgE-reactive 40–45-kDa protein components. By 2D immunoblotting, we detected a 42-kDa protein spot with an isoelectric point (p I ) of 4.8; the protein was highly reactive to IgE and was designated MGp42. Full-length MGp42 cDNA contained a 1908-bp open reading frame encoding 635 amino acid residues (calculated molecular mass, 69.7kDa; p I , 6.02). The N-terminal MGp42 sequence started from the 250th residue (Asp-250) of the deduced amino acid sequence and consisted of 386 amino acid residues; these results are consistent with those of 2D immunoblotting. MGp42 showed sequence similarity to members of the heat shock protein 70 (hsp70) family. Immunoblot inhibition tests revealed no IgE cross-reactivity between MGp42 and human HSP70. Conclusions MGp42 may be a cleavage product of intact HSP70. This novel M. globosa allergen could be useful for the diagnosis of AD.