title: Inhibition of transglutaminase by synthetic tyrosine melanin.
abstract: Transglutaminases catalyze the cross-linking and amine incorporation of proteins, and are implicated in various biological phenomena. Previously, we found a high molecular mass transglutaminase-inhibitory substance produced by Streptomyces lavendulae Y-200 that appeared to be a melanin substance. Here, we report that synthetic tyrosine melanin inhibited various types of transglutaminases. Tyrosine melanin inhibited tissue-type transglutaminase in a competitive manner with a glutamine substrate, and also inhibited the cross-linking of casein catalyzed by a tissue-type transglutaminase. The melanized hemolymph of the silkworm and melanin solutions prepared from melanin precursors inhibited tissue-type transglutaminase. These results suggested that the melanin substances generally inhibit transglutaminases.
authors.affiliation: Department of Applied Biology, Kyoto Institute of Technology, Matsugasaki, Japan. ikura@ipc.kit.ac.jp
authors.forename: Koji
authors.initials: K
authors.lastname: Ikura
authors.forename: Chiemi
authors.initials: C
authors.lastname: Otomo
authors.forename: Shunji
authors.initials: S
authors.lastname: Natsuka
authors.forename: Akira
authors.initials: A
authors.lastname: Ichikawa
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Wakamatsu
authors.forename: Shosuke
authors.initials: S
authors.lastname: Ito
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Taoguchi
mesh_terms: D000818:Animals; D012831:Bombyx / Q000201:enzymology; D002364:Caseins / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D008099:Liver / Q000201:enzymology; D008543:Melanins / Q000138:chemical synthesis* / Q000494:pharmacology*; D011503:Transglutaminases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D014443:Tyrosine / Q000138:chemical synthesis* / Q000494:pharmacology*
chemical_list: D002364:Caseins; D008543:Melanins; D014443:Tyrosine; D011503:Transglutaminases