HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Williamson, I. P. Articles by Wakil, S. J. Search for Related Content PubMed PubMed Citation Articles by Williamson, I. P. Articles by Wakil, S. J. Social Bookmarking                      What's this?

Studies on the Mechanism of Fatty Acid Synthesis

XVII. PREPARATION AND GENERAL PROPERTIES OF ACETYL COENZYME A AND MALONYL COENZYME A-ACYL CARRIER PROTEIN TRANSACYLASES

From the ¹ From the Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27706

Acetyl coenzyme A-acyl carrier protein transacylase (acetyl transacylase) and malonyl coenzyme A-acyl carrier protein transacylase (malonyl transacylase) have been purified 90- and 255-fold, respectively, from Escherichia coli extracts and exhibited the following properties.

Acetyl transacylase is heat-labile whereas malonyl transacylase is comparatively heat-stable, 80% of its activity surviving for 20 min at 80°. Both enzymes have pH optima in the region of 6.5. The reactions are readily reversible, and equilibrium constants are 2.09 for acetyl transacylase and 2.33 for malonyl transacylase. Inhibition of the enzymes by N-ethylmaleimide and iodoacetamide demonstrates that both are sulfhydryl enzymes.

Acetyl transacylase is relatively specific for acetyl-CoA but can transacylate coenzyme A esters of propionic, butyric, and hexanoic acids at a rate of 23.4, 9.8, and 4.5% that of acetyl-CoA, respectively.

Evidence is presented in support of a mechanism of action of acetyl transacylase involving the intermediary formation of an acetyl—S—enzyme which can then transfer the acetyl group to acyl carrier protein or coenzyme A.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				L. Serre, E. C. Verbree, Z. Dauter, A. R. Stuitje, and Z. S. Derewenda The Escherichia coli Malonyl-CoA:Acyl Carrier Protein Transacylase at 1.5-Å Resolution J. Biol. Chem., June 2, 1995; 270(22): 12961 - 12964. [Abstract] [Full Text] [PDF]

				R. M. Bell and D. E. Koshland Jr. Covalent Enzyme-Substrate Intermediates Science, June 18, 1971; 172(3989): 1253 - 1256. [Abstract] [PDF]