In Vitro Hydrolysis of Zinc Chlorophyllide a Homologues by a BciC Enzyme

Autor:	Hitoshi Tamiaki, Mitsuaki Hirose, Jiro Harada
Rok vydání:	2020
Předmět:	chemistry.chemical_classification 0303 health sciences Decarboxylation Stereochemistry Carboxylic acid 030302 biochemistry & molecular biology Chlorosome Biochemistry Enzyme catalysis 03 medical and health sciences Hydrolysis Enzyme chemistry Enzymatic hydrolysis Photosynthetic bacteria
Zdroj:	Biochemistry. 59:4622-4626
ISSN:	1520-4995 0006-2960
Popis:	Chlorosomes in green photosynthetic bacteria are the largest and most efficient light-harvesting antenna systems of all phototrophs. The core part of chlorosomes consists of bacteriochlorophyll c, d, or e molecules. In their biosynthetic pathway, a BciC enzyme catalyzes the removal of the C132-methoxycarbonyl group of chlorophyllide a. In this study, the in vitro enzymatic reactions of chlorophyllide a analogues, C132-methylene- and ethylene-inserted zinc complexes, were examined using a BciC protein from Chlorobaculum tepidum. As the products, their hydrolyzed free carboxylic acids were observed without the corresponding demethoxycarbonylated compounds. The results showed that the in vivo demethoxycarbonylation of chlorophyllide a by an action of the BciC enzyme would occur via two steps: (1) an enzymatic hydrolysis of a methyl ester at the C132-position, followed by (2) a spontaneous (nonenzymatic) decarboxylation in the resulting carboxylic acid.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::8fe456fb6469f2cf9e010de993791e0d https://doi.org/10.1021/acs.biochem.0c00850 Zobrazit plný text záznamu