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B6db references: sdacpc

type Journal Article
authors Jia, Y. J.; Kakuta, Y.; Sugawara, M.; Igarashi, T.; Oki, N.; Kisaki, M.; Shoji, T.; Kanetuna, Y.; Horita, T.; Matsui, H.; Honma, M.
title Synthesis and degradation of 1-aminocyclopropane-1-carboxylic acid by Penicillium citrinum
journal Biosci Biotechnol Biochem
Activity 4.4.1.14
Family 4.4.1.14
ui SdacPc
year (1999)
volume 63
number 3
pages 542-9
 
keywords Amino Acids/biosynthesis/*metabolism
abstract 1-Aminocyclopropane-1-carboxylic acid (ACC), which is a precursor of ethylene in plants, has never been known to occur in microorganisms. We describe the synthesis of ACC by Penicillium citrinum, purification of ACC synthase [EC 4.4.1.14] and ACC deaminase [EC 4.1.99.4], and their properties. Analyses of P. citrinum culture showed occurrence of ACC in the culture broth and in the cell extract. ACC synthase was purified from cells grown in a medium containing 0.05% L-methionine and ACC deaminase was done from cells incubated in a medium containing 1% 2-aminoisobutyrate. The purified ACC synthase, with a specific activity of 327 milliunit/mg protein, showed a single band of M(r) 48,000 in SDS-polyacrylamide gel electrophoresis. The molecular mass of the native enzyme by gel filtration was 96,000 Da. The ACC synthase had the Km for S-adenosyl-L-methionine of 1.74 mM and kcat of 0.56 s-1 per monomer. The purified ACC deaminase, with a specific activity of 4.7 unit/mg protein, showed one band in SDS-polyacrylamide gel electrophoresis of M(r) 41,000. The molecular mass of the native ACC deaminase was 68,000 Da by gel filtration. The enzyme had a Km for ACC of 4.8 mM and kcat of 3.52 s-1. The presence of 7 mM Cu2+ in alkaline buffer solution was effective for increasing the stability of the ACC deaminase in the process of purification.
last changed 2008/04/25 17:36

B6db references