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Antimelanogenic chemicals with in vivo efficacy against skin pigmentation in guinea pigs
홍승덕,윤다영,이승민,한상배,김영수 대한약학회 2014 Archives of Pharmacal Research Vol.37 No.10
Ultraviolet (UV) radiation under sunlightstimulates skin pigmentation through immediately affectingthe oxidative modification of existing melanin pigmentsand the spatial redistribution of pigmentedmelanosomes followed by the up-regulation of melanogenicgenes in delayed kinetics. However, abnormalaccumulation and synthesis of melanin biopolymers areresponsible for skin disorders with more pigmented patches. Chemical-based regulation of the hyperpigmenteddisorders has been a long-standing goal for cosmetic andpharmaceutical applications. A large number of thechemicals with antimelanogenic activity have met withlimited or no success in the treatment of skin patients, sincethey may not overcome the challenge of penetrating theskin barrier. Guinea pig skin displays similar kineticparameters to human skin in the transdermal absorption ofnumerous chemicals, thus can serve as the surrogate forhuman skin. Here, we provide a concise review of ourcurrent understanding of the chemical-based therapyagainst skin hyperpigmentation in UV-irradiated guineapig models, suggest molecular mechanisms of the actionand emphasize the translation from preclinical outcomes toskin patients.
The Mechanism of Acyl Phosphatidyl Glycerol Biosynthesis in Escherichia coli B and B/r
조기승,홍승덕,장정순,이강석,Cho, Key-Seung,Hong, Seung-Duk,Chang, Chung-Soon,Lee, Kang-Suk 생화학분자생물학회 1975 한국생화학회지 Vol.8 No.1
본 연구는 대장균 strain B와 B/r(Escherichia coli Band B/r)의 세포막 분획에의 해서 phosphatidyl glycerol이 3-sn-phosphatidyl-1'-(3'-acyl(-sn-glycerol(acyl phosphatidyl glycerol 로 전환되는 기작을 밝혔다. 이 과정에서 phosphatidyl glycerol은 더 간단한 화합물로 분해된 후 acyl phosphatidyl glycerol로 합성되는 것이 아니라 직접 acyl group이 옮겨져서 ester 결합을 하는 것으로 생각된다. Phosphatidyl glycerol이 acyl phosphatidyl glycerol로 전환되는 반응을 촉매하는 효소인 acyl phosphatidyl glycerol synthetase는 E. coli homogenate의 세포막 분획에 존재하는 것으로 밝혀졌다. Phosphatidyl glycerol이 acyl phosphatidyl glycerol로 전환됨에 있어서 두 개의 다른 반응 기작을 밝혔다. 두 분자의 phosphatidyl glycerol이 한 분자의 acyl phosphatidyl glycerol 을 합성하는 즉 phosphatidyl glycerol이 acyl group의 공여체와 수용체로 각각 작용하는 반응과 다른 반응은 phosphatidyl glycer이 이 수용체로 phosphatidyl ethanolamine이 acyl group 공여체로 작용하는 기작이다. Acyl phosphatidyl glycerol 생합성에 있어서 최적 pH 는 7.0이며 최적 calcium ion 농도는 6.0mM 이었다. 이 실험 결과는 대장균의 phosphatidyl glycerol의 새로운 대사과정을 밝혔다. The present study has shown that phosphatidyl glycerol was converted to 3-sn-phosphatidyl-1'-(3'-acyl)-sn-glycerol (acyl phosphatidyl glycerol) by cell free extracts of Escherichia coli Band B/r. In this process, phosphatidyl glycerol was esterified directly rather than degraded to simpler compounds which are subsequently incorporated into acyl phosphatidyl glycerol. The enzyme, "acyl phosphatidyl glycerol synthetase", which catalyzes the conversion of phosphatidyl glycerol to acyl phosphatidyl glycerol was found to reside solely in the praticulate fraction of E. coli homogenates. Two separate reactions were identified where one molecule of acyl phosphatidyl glycerol was synthesized from two molecules of phosphatidyl glycerol, in which phosphatidyl glycerol acted both as an acyl acceptor and a donor. In the other reaction, phosphatidyl ethanolamine appears to act as an acyl donor to synthesize acyl phosphatidyl glycerol. The formation of acyl phosphatidyl glycerol has an optimum pH value at pH 7.0 and calcium concentration of 6.0 mM. These results show a new pathway for the turnover of phosphatidyl glycerol in Escherichia coli.