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Richard A. Spritz - One of the best experts on this subject based on the ideXlab platform.
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frequent intragenic deletion of the p gene in tanzanian patients with type ii oculocutaneous albinism oca2
American Journal of Human Genetics, 1995Co-Authors: Richard A. Spritz, Kazuyoshi Fukai, Stuart A Holmes, J LuandeAbstract:Type II oculocutaneous albinism (OCA2) is an autosomal recessive disorder in which the biosynthesis of Melanin Pigment is reduced in the skin, hair, and eyes. OCA2, which results from mutations of the P gene, is the most frequent type of albinism in African and African-American patients. OCA2 is especially frequent in Tanzania, where it occurs with an incidence of approximately 1/1,400. We have identified abnormalities of the P gene in each of 13 unrelated patients with OCA2 from Tanzania. One of these, a deletion of exon 7, is strongly predominant, accounting for approximately 77% of mutant alleles in this group of patients.
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diverse mutations of the p gene among african americans with type ii tyrosinase positive oculocutaneous albinism oca2
Human Molecular Genetics, 1994Co-Authors: Seung Taek Lee, Robert D Nicholls, Rhonda E Schnur, Leticia C Guida, Jennifer Lukuo, Nancy B Spinner, Elaine H Zackai, Richard A. SpritzAbstract:Type II (tyrosinase-positive) oculocutaneous albinism (OCA2) is an autosomal recessive disorder in which the biosynthesis of Melanin Pigment is reduced in the skin, hair, and eyes. OCA2, which we have shown results from mutations of the P gene in Caucasians, is the most prevalent type of oculocutaneous albinism in African and African-American patients with OCA. We have identified abnormalities of the P gene in seven unrelated African-American patients with OCA2, including three large deletions, two small in-frame deletions, and six different point mutations. None of these appears to be predominant among African-American patients with OCA2.
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Molecular genetics of oculocutaneous albinism.
Human Molecular Genetics, 1994Co-Authors: Richard A. SpritzAbstract:Albinism is a group of genetic disorders characterized by deficient synthesis of Melanin Pigment. In oculocutaneous albinism (OCA) the Pigment deficiency involves the skin, hair, and eyes, whereas in ocular albinism (OA) the defect involves principally the visual system. Type I (tyrosinase-deficient) OCA results from deficient catalytic activity of tyrosinase, which catalyzes at least three steps in the Melanin biosynthetic pathway. Type II (tyrosinase-positive) OCA results from abnormalities of the 'P' polypeptide, which may be a melanosomal tyrosine transporter. At least some forms of OA appear to represent mild presentations of types I and II OCA. The causes of several other forms of albinism have not yet been identified. Recent application of molecular genetic techniques to the study of these disorders has led to greatly improved knowledge of their molecular pathogenesis and relationships, and paves the way to improved diagnosis, carrier detection and prenatal diagnosis, and even to eventual treatment.
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molecular genetics of oculocutaneous albinism
Seminars in Dermatology, 1993Co-Authors: Richard A. SpritzAbstract:Oculocutaneous albinism (OCA) is a group of autosomal recessive disorders characterized by deficient synthesis of Melanin Pigment. Type I (tyrosinase-deficient) OCA results from deficient enzymatic activity of tyrosinase, which catalyzes at least three steps in the Melanin biosynthetic pathway. Type II (tyrosinase-positive) OCA results from abnormalities of the "P" polypeptide. Recent application of molecular genetic techniques to the study of these disorders has led to extraordinary advances in knowledge of their molecular pathogenesis, paving the way to improved diagnosis, carrier detection, and even treatment.
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Tyrosinase gene mutations in type I (tyrosinase-deficient) oculocutaneous albinism define two clusters of missense substitutions.
American journal of medical genetics, 1992Co-Authors: R K Tripathi, Kathleen M. Strunk, Lutz B. Giebel, Richard G. Weleber, Richard A. SpritzAbstract:Type I (tyrosinase-deficient) oculocutaneous albinism (OCA) results from mutations of the gene encoding tyrosinase, the enzyme that catalyzes the first 2 steps of Melanin Pigment biosynthesis. In type IA (tyrosinase-negative) OCA tyrosinase enzymatic activity is completely absent, and in type IB ("yellow") OCA tyrosinase activity is greatly reduced. Here, we describe 11 novel mutations of the tyrosinase gene in Caucasian patients with these 2 forms of type I OCA. Type I OCA in Caucasians appears to result from a great variety of different uncommon alleles. More than 80% of the known missense substitutions associated with type I OCA cluster within 2 relatively small regions of the tyrosinase polypeptide, suggesting that these may correspond to functionally important sites within the enzyme.
Taegyu Nam - One of the best experts on this subject based on the ideXlab platform.
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:AbstractTyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-...
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:Tyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-whitening cosmetics is also briefly discussed.
Andrzej Slominski - One of the best experts on this subject based on the ideXlab platform.
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the role of Melanin Pigment in melanoma
Experimental Dermatology, 2015Co-Authors: Radomir M Slominski, Michal A Zmijewski, Andrzej SlominskiAbstract:The synthesis of Melanin, a multistep and highly regulated path-way, represents a major differentiated function of normal andmalignant melanocytes (reviewed in Refs 1,2). Although the mainfunction of Melanin is to protect against UV-induced damage,Melanin Pigment can also regulate epidermal homeostasis andthus can affect melanoma behaviour (3–7).Recently, Sarna et al. (8) started to test a hypothesis that mela-nin Pigment can affect the behaviour of melanoma cells in vitro.The authors had shown that the presence of Melanin Pigmentaffected the elastic properties of the cells as well as the transmigra-tion abilities with the inhibitory effects being mechanical in nat-ure. They had proposed that cell elasticity may play a key role inthe efficiency of melanoma cells spread in vivo and expect thattheir findings can contribute to the better understanding of theprocess of metastasis of malignant melanoma.We agree with the authors that the mechanical (physical) effectof loading of melanoma cells with Melanin granules can attenuatethe movement of malignant melanocytes towards the metastaticpath. This would be expected for stage 1 melanomas that arelocalized in the epidermis and dermis. However, other parameterssuch as cell proliferation, changes in cell cytoskeleton and motilityneed to be further investigated. It must be noted that SKMEL-188cells, as well as the Bomirski Ab and AbC1 melanoma cells, whencultured in media supplemented with
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Melanin Pigmentation in mammalian skin and its hormonal regulation
Physical Review, 2004Co-Authors: Andrzej Slominski, Desmond J Tobin, Shigeki Shibahara, Jacobo WortsmanAbstract:Cutaneous Melanin Pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. Melanogenesis is under complex regulatory co...
Sang Yeul Lee - One of the best experts on this subject based on the ideXlab platform.
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:AbstractTyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-...
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:Tyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-whitening cosmetics is also briefly discussed.
Namhuk Baek - One of the best experts on this subject based on the ideXlab platform.
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:AbstractTyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-...
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natural semisynthetic and synthetic tyrosinase inhibitors
Journal of Enzyme Inhibition and Medicinal Chemistry, 2016Co-Authors: Sang Yeul Lee, Namhuk Baek, Taegyu NamAbstract:Tyrosinase plays a pivotal role in the synthesis of Melanin Pigment synthesis on skin utilizing tyrosine as a substrate. Melanin is responsible for the protection against harmful ultraviolet irradiation, which can cause significant pathological conditions, such as skin cancers. However, it can also create esthetic problems when accumulated as hyperPigmented spots. Various skin-whitening ingredients which inhibit tyrosinase activity have been identified. Some of them, especially ones with natural product origins, possess phenolic moiety and have been employed in cosmetic products. Semi-synthetic and synthetic inhibitors have also been developed under inspiration of the natural inhibitors yet some of which have no phenolic groups. In this review, tyrosinase inhibitors with natural, semi-synthetic and synthetic origins are listed up with their structures, activities and characteristics. Further, a recent report on the adverse effect of a natural Melanin synthesis inhibitor which was included in skin-whitening cosmetics is also briefly discussed.