Eumelanin is a heteropolymer that is generally composed of hydroxylated indole residues and plays diverse protective functions in various species.Melanin is derived from the amino acid tyrosine and production of melan...Eumelanin is a heteropolymer that is generally composed of hydroxylated indole residues and plays diverse protective functions in various species.Melanin is derived from the amino acid tyrosine and production of melanin is a highly complex oxidative process with a number of steps that can either proceed enzymatically or non-enzymatically.Although melanin plays important protective roles in many species,during melanization,particularly in steps that can proceed non-enzymatically,many toxic intermediates are produced,including semiquinones,dopaquinone,indole-quinones and moreover,the production of many reactive oxygen species.To mitigate the production of reactive species,a number of proteins that regulate the biochemical process of melanization have evolved in various living species,which is closely related to adaptation and physiological requirements.In this communication,we discuss differences between non-enzymatic and enzymatic processes of melanization and the enzymatic regulation of melanization in difference species with an emphasis on differences between mammals and insects.Comparison between melanization and insect sclerotization is also emphasized which raises some interesting questions about the current models of these pathways.展开更多
基金supported in part by an NIH grant AI 19769.Chris Vavricka is supported by Chinese Academy of Sciences Fellowship for Young International Scientists(2009Y2BS2)the National Natural Science Foundation of China(NSFC)Research Fund for International Young Scientists(Grant No.31050110126)。
文摘Eumelanin is a heteropolymer that is generally composed of hydroxylated indole residues and plays diverse protective functions in various species.Melanin is derived from the amino acid tyrosine and production of melanin is a highly complex oxidative process with a number of steps that can either proceed enzymatically or non-enzymatically.Although melanin plays important protective roles in many species,during melanization,particularly in steps that can proceed non-enzymatically,many toxic intermediates are produced,including semiquinones,dopaquinone,indole-quinones and moreover,the production of many reactive oxygen species.To mitigate the production of reactive species,a number of proteins that regulate the biochemical process of melanization have evolved in various living species,which is closely related to adaptation and physiological requirements.In this communication,we discuss differences between non-enzymatic and enzymatic processes of melanization and the enzymatic regulation of melanization in difference species with an emphasis on differences between mammals and insects.Comparison between melanization and insect sclerotization is also emphasized which raises some interesting questions about the current models of these pathways.
