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Klaus Biemann - One of the best experts on this subject based on the ideXlab platform.
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amino acid sequence of a protease inhibitor isolated from sarcophaga bullata determined by mass spectrometry
Protein Science, 2008Co-Authors: Ioannis A Papayannopoulos, Klaus BiemannAbstract:The amino acid sequence of a protease inhibitor isolated from the hemolymph of Sarcophaga bullata larvae was determined by tandem mass spectrometry. Homology considerations with respect to other protease inhibitors with known primary structures assisted in the choice of the procedure followed in the sequence determination and in the alignment of the various peptides obtained from specific chemical cleavage at cysteines and enzyme digests of the S. bullata protease inhibitor. The resulting sequence of 57 residues is as follows: Val Asp Lys Ser Ala Cys Leu Gln Pro Lys Glu Val Gly Pro Cys Arg Lys Ser Asp Phe Val Phe Phe Tyr Asn Ala Asp Thr Lys Ala Cys Glu Glu Phe Leu Tyr Gly Gly Cys Arg Gly Asn Asp Asn Arg Phe Asn Thr Lys Glu Glu Cys Glu Lys Leu Cys Leu.
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Amino acid sequence of a protease inhibitor isolated from Sarcophaga bullata determined w
1992Co-Authors: Klaus BiemannAbstract:The amino acid sequence of a protease inhibitor isolated from the hemolymph of Sarcophaga bullata larvae was determined by tandem mass spectrometry. Homology considerations with respect to other protease inhibitors with known primary structures assisted in the choice of the procedure followed in the sequence determination and in the alignment of the various peptides obtained from specific chemical cleavage at cysteines and enzyme digests of the S. bullata protease inhibitor. The resulting sequence of 57 residues is as follows: Val Asp Lys Ser Ala Cys Leu Gln Pro Lys Glu Val Gly Pro Cys Arg Lys Ser Asp Phe Val Phe Phe Tyr Asn Ala Asp Thr Lys Ala Cys Glu Glu Phe Leu Tyr Gly Gly Cys Arg Gly Asn Asp Asn Arg Phe Asn Thr Lys Glu Glu Cys Glu Lys Leu Cys Leu.
Cunliu Zhou - One of the best experts on this subject based on the ideXlab platform.
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l arginine and l lysine degrade troponin t and l arginine dissociates actomyosin their roles in improving the tenderness of chicken breast
Food Chemistry, 2020Co-Authors: Yinyin Zhang, Hongmei Fang, Daojing Zhang, Yajun Huang, Li Chen, Pengqi Bao, Cunliu ZhouAbstract:Abstract This work investigated the effects of L-arginine (Arg) and L-lysine (Lys) on the tenderness of chicken breast and explored the possible mechanisms underlying this effect for the first time. The results showed that both Arg and Lys decreased the shear force and increased the pH value, sarcomere length and myofibrillar fragmentation index as well as degraded the troponin-T by keeping calpain activity in chicken breast. In addition, Arg effectively reduced Ca2+/Mg2+-ATPase activities and promoted actomyosin dissociation. These results indicated that both Arg and Lys could enhance the tenderness of chicken breast, and it could also explain why Arg was more effective than Lys in improving the tenderness of chicken breast. These results will help facilitate the development of industrial-scale methods for improving the tenderness of meat products.
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effects of basic amino acid on the tenderness water binding capacity and texture of cooked marinated chicken breast
Lwt - Food Science and Technology, 2020Co-Authors: Yinyin Zhang, Hongmei Fang, Daojing Zhang, Yajun Huang, Li Chen, Pengqi Bao, Cunliu ZhouAbstract:Abstract This work investigated the effects of basic amino acids such as l -arginine (Arg)/ l -lysine (Lys) on the physicochemical properties of cooked marinated chicken breast (CMCB) as well as the possible mechanism underlying these effects. The results indicated that shearing force decreased from 13.3 N to 10.0 N and cooking loss decreased from 38.3 g/100 g–26 g/100 g when Lys increased from 0 g/100 g–0.4 g/100 g, while shearing force decreased to 8.8 N and cooking loss decreased to 28 g/100 g at 0.4 g Arg/100 g. Furthermore, Arg/Lys improved the textural parameters and increased pH value. Low field-nuclear magnetic resonance showed that Arg shortened the relaxation times of T21 from 50 ms to 38 ms and Arg/Lys increased the peak area percentage (P21) for T21 from 93.6 to 97. Arg/Lys promoted the extraction of salt-soluble meat proteins from 54 mg/g to 78.6 mg/g. Scanning electron microscopy illustrated that Arg and Lys narrowed the gaps between muscle fibers at 0.6 g/100 g and at 0.4 g/100 g, respectively. The results disclosed that Arg/Lys could improve the physicochemical properties of CMCB, and thus showing a potential for the manufacture of cooked marinated meat products.
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l-Lysine/l-arginine/l-cysteine synergistically improves the color of cured sausage with NaNO2 by hindering myoglobin oxidation and promoting nitrosylmyoglobin formation.
Food Chemistry, 2019Co-Authors: Cheng Ning, Hongmei Fang, Yuxiang Tang, Cunliu ZhouAbstract:Abstract This study aimed to evaluate the effects of l -lysine (Lys)/ l -arginine (Arg)/ l -cysteine (Cys) on the color of cured sausage and the possible mechanism underlying these effects. The results indicated that the combined addition of Arg/Lys/Cys and NaNO2 effectively increased the a* values and nitroso pigment content but decreased the MetMb(Fe3+) content in cured sausage, compared with the individual addition of Arg/Lys/Cys and NaNO2. The cured sausage treated with combined Arg/Lys/Cys and NaNO2 contained significantly lower residual nitrite than those treated with only NaNO2. UV-vis spectroscopy and electron paramagnetic resonance spectroscopy revealed that pentacoordinate nitrosyl ferrohemochrome was the main pigment component in the cured sausage treated with NaNO2 or combined Arg/Lys/Cys and NaNO2 and higher content in the latter one. The results suggest that Arg/Lys/Cys hindered myoglobin oxidation and promoted pentacoordinate nitrosylmyoglobin formation, which could contribute to the improved color of cured sausage. The results are of interest in the meat industry.
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l–Arginine/l–lysine improves emulsion stability of chicken sausage by increasing electrostatic repulsion of emulsion droplet and decreasing the interfacial tension of soybean oil-water
Food Hydrocolloids, 2019Co-Authors: Xiaoxu Zhu, Cheng Ning, Cunliu ZhouAbstract:Abstract The effects of l –arginine (Arg) and l –lysine (Lys) on the emulsifying properties of the salt-soluble meat proteins (SSMPs)–soybean oil emulsion (SSOE) and soybean oil–water emulsion (SWE) were evaluated to ascertain their roles in improving the emulsion stability of sausage. The results indicated that Arg/Lys addition or increasing pH increased the emulsifying activity/stability index and the absolute ζ–potential of emulsion droplets but decreased the creaming index, apparent viscosity, and mean particle size of SSOE. Amino acid analysis showed that Arg/Lys accumulated at the interface of the emulsion droplets. Arg/Lys also decreased the surface tension of SWE at 0.002% but increased the stability of SWE at 0.1% – 0.3%. In summary, Arg/Lys improved the stability of emulsified sausage by increasing the electrostatic repulsion of emulsion droplets and decreasing the interfacial tension of soybean oil-water.
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l-Lysine and l-arginine inhibit myosin aggregation and interact with acidic amino acid residues of myosin: The role in increasing myosin solubility.
Food Chemistry, 2017Co-Authors: Yadong Zheng, Xiaoxu Zhu, Cunliu ZhouAbstract:The objective of this paper is to investigate the potential affecting mechanisms of l-lysine (Lys)/l-arginine (Arg) on myosin solubility. The results showed that both Lys and Arg increased the solubility of myosin at the examined pH values. Additionally, both Lys and Arg decreased the hydrodynamic size of myosin but increased the hydration capacity (HC), the surface aromatic hydrophobicity of myosin, the surface tension of the myosin solution and the absolute transfer free energy (TFE) of the major amino acids that constitute myosin. The results indicate that the properties of Lys or Arg that result in an inhibition of myosin aggregation and an interaction with hydrophobic amino acid residues may play important roles in increasing the myosin solubility. The results are attractive to the meat industry.
Ioannis A Papayannopoulos - One of the best experts on this subject based on the ideXlab platform.
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amino acid sequence of a protease inhibitor isolated from sarcophaga bullata determined by mass spectrometry
Protein Science, 2008Co-Authors: Ioannis A Papayannopoulos, Klaus BiemannAbstract:The amino acid sequence of a protease inhibitor isolated from the hemolymph of Sarcophaga bullata larvae was determined by tandem mass spectrometry. Homology considerations with respect to other protease inhibitors with known primary structures assisted in the choice of the procedure followed in the sequence determination and in the alignment of the various peptides obtained from specific chemical cleavage at cysteines and enzyme digests of the S. bullata protease inhibitor. The resulting sequence of 57 residues is as follows: Val Asp Lys Ser Ala Cys Leu Gln Pro Lys Glu Val Gly Pro Cys Arg Lys Ser Asp Phe Val Phe Phe Tyr Asn Ala Asp Thr Lys Ala Cys Glu Glu Phe Leu Tyr Gly Gly Cys Arg Gly Asn Asp Asn Arg Phe Asn Thr Lys Glu Glu Cys Glu Lys Leu Cys Leu.
Kazuhisa Nakayama - One of the best experts on this subject based on the ideXlab platform.
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Processing of mutated proinsulin with tetrabasic cleavage sites to bioactive insulin in the non‐endocrine cell line, COS‐7
FEBS Letters, 1992Co-Authors: Masahiko Yanagita, Kazuhisa Nakayama, Toshiyuki TakeuchiAbstract:The amino acid sequence, Arg−4-X−3-Lys/Arg−2-Arg−1 ↓ X+1, is thought to be a consensus processing site for a constitutive secretory pathway in non-endocrine cells. We created a mutant proinsulin DNA with a peptide structure of B chain-Arg-Arg-Lys-Arg-C peptide-Arg-Arg-Lys-Arg-A chain, which compares to the native proinsulin structure of B chain-Arg-Arg-C peptide-Lys-Arg-A chain. When the mutant insulin was expressed in a monkey kidney-derived cell line, COS-7, approximately 60% of the total immunoreactive insulin appeared as mature insulin in the culture medium. This conversion to the mature form was strikingly facilitated by co-expressing the mutant proinsulin with furin, a homologue of the yeast endoprotease, Kex2.
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arg x lys arg arg motif as a signal for precursor cleavage catalyzed by furin within the constitutive secretory pathway
Journal of Biological Chemistry, 1991Co-Authors: Masahiro Hosaka, Masami Nagahama, Kazuo Murakami, Tsuyoshi Watanabe, Kiyotaka Hatsuzawa, J Ikemizu, Kazuhisa NakayamaAbstract:Abstract Many peptide hormones are produced from larger precursors by endoproteolysis at pairs of basic amino acids (e.g. Lys-Arg and Arg-Arg) within the regulated secretory pathway in endocrine cells. However, many other secretory and membrane proteins appear to be produced from precursors through cleavage at multiple, rather than paired, basic residues within the constitutive secretory pathway in non-endocrine cells. By surveying various precursors processed constitutively, we noticed that most of them have the consensus sequence, Arg-X-Lys/Arg-Arg (RXK/RR), at the cleavage site. When expressed in endocrine and non-endocrine cells, a precursor with the RXKR sequence was cleaved in both types of cells, whereas that with the Lys-Arg pair was cleaved only in the endocrine cells. When the RXKR precursor was coexpressed with furin and PC3, both of which are mammalian homologues of the yeast precursor-processing endoprotease Kex2, in non-endocrine cells, enhancement of the precursor cleavage by furin but not by PC3 was observed. By contrast, when the Lys-Arg precursor was coexpressed with the two mammalian proteases in endocrine cells with no endogenous processing activity at dibasic sites, it was cleaved only by PC3. These results indicate that the basic pair and the RXK/RR sequence are the signals for precursor cleavages catalyzed by PC3 within the regulated secretory pathway and by furin within the constitutive pathway, respectively.
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Sequence requirements for prohormone processing in mouse pituitary AtT-20 cells. Analysis using prorenins as model substrates.
European Journal of Biochemistry, 1991Co-Authors: Masami Nagahama, Kazuhisa Nakayama, Kazuo MurakamiAbstract:Although cleavage of peptides at sites marked by paired basic amino acids is a common feature of prohormone processing, little is known about the properties of endoprotease(s) responsible for cleavage of the precursor. To examine the cleavage specificity of a processing endoprotease, we have altered the Lys-Arg cleavage site of human prorenin to Arg-Arg, Lys-Lys and Arg-Lys by site-directed mutagenesis, and expressed the native and mutated precursors in mouse pituitary AtT-20 cells which are known to process foreign prohormones, including prorenin, at paired basic sites during the regulated secretory process. All native and mutated human prorenins were sorted into the regulated secretory pathway. The mutated precursor with Arg-Arg instead of the Lys-Arg native pair was processed at about half the efficiency of the native one, while the Lys-Lys and Arg-Lys mutants were not processed. Rat prorenin, which naturally has a Lys-Lys pair, was not processed in the cells. In addition, mouse Ren2 prorenin, which has a Ser residue next to the Lys-Arg pair, but not mouse Ren1 prorenin, which has a Pro residue next to the pair, was processed. These results suggest that the Arg residue at the COOH side of the basic pair is essential for cleavage of prorenins by a processing enzyme during the regulated secretory process in AtT-20 cells, although the NH2-side Lys residue also plays a role. The results also demonstrate that the processing enzyme cannot cleave the Arg-Pro peptide bond.
Katsuji Nishi - One of the best experts on this subject based on the ideXlab platform.
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isolation and characterization of an alanyl aminopeptidase from rat liver cytosol as a puromycin sensitive enkephalin degrading aminopeptidase
Biological Chemistry, 1998Co-Authors: Yoshio Yamamoto, Yao Hua Li, Iwao Ohkubo, Kai Huang, Katsuji NishiAbstract:: Alanyl aminopeptidase (AAP-S) was purified to homogeneity from rat liver cytosol. The molecular weight of the purified enzyme was calculated to be approximately 100,000 on Sephacryl S-200 HR and to be 90,000 on SDS-PAGE in the presence of beta-mercaptoethanol. These findings suggested that the enzyme exists as a monomeric form in rat liver cytosol. The enzyme rapidly hydrolyzed the substrates Ala-, Tyr- and Met-MCAs, and moderately hydrolyzed Arg-, Lys-, Leu-, Phe- and Lys-Ala-MCAs at pHs ranging from 7.5to 8.0. The enzyme also hydrolyzed several amino acid 4-methyl-coumaryl-7-amide (MCA) substrates. The order for k(cat)/Km values of AAP-S at the optimal pH (pH 7.5) was Lys->Met->Arg->Ala->Leu->Phe->Tyr->Lys-Ala-MCAs. It was strongly inhibited by bestatin, leuhistin, actinonin, amastatin, 1, 10-phenanthroline, PCMBS, Zn2+, Cd2+, Co2+, Cu2+ and Hg2+, and puromycin. The amino acid sequence of the first 43 residues of the enzyme was determined as Pro1-Glu-Lys-Arg-Pro5-Phe-Glu-Arg-Leu-Pro10-Thr-Glu-Val-Ser-Pro 15-Ile-Asn-Tyr-Ser-Leu20-(Cys)-Leu-Lys-Pro-Asp25-Leu-Leu- Asp-Phe-Thr30-Phe-Glu-Gly-Lys-Leu35-Glu-Ala-Ala-Ala-Gln40 -Val-Arg-Gln-. This N-terminal amino acid sequence is almost identical with those of puromycin-sensitive enkephalin-degrading aminopeptidases in rat and human brains, and the mouse neuroblastoma cell line Neuro2A. These findings suggest that the AAP-S from rat liver cytosol is a puromycin-sensitive aminopeptidase. Furthermore, with immunohistochemistry the enzyme was strongly stained in the cytosol of the rat liver cells.