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 Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Pope, M. R. Articles by Ludden, P. W. Search for Related Content PubMed PubMed Citation Articles by Pope, M. R. Articles by Ludden, P. W. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 261, Issue 22, 10104-10111, 08, 1986

N-glycohydrolysis of adenosine diphosphoribosyl arginine linkages by dinitrogenase reductase activating glycohydrolase (activating enzyme) from Rhodospirillum rubrum

MR Pope, LL Saari and PW Ludden

The reaction catalyzed by the activating enzyme for dinitrogenase reductase from Rhodospirillum rubrum has been studied using an ADP- ribosyl hexapeptide, obtained from proteolysis of inactive dinitrogenase reductase, and synthetic analogs such as N alpha-dansyl-N omega-ADP-ribosylarginine methyl ester. The activating enzyme catalyzed N-glycohydrolysis of the ribosyl-guanidinium linkage releasing ADP- ribose and regenerating an unmodified arginyl guanidinium group. Optimal glycohydrolysis of the low molecular weight substrates occurred at pH 6.6 and required 1 mM MnCl2, but did not require ATP. The ADP- ribosyl hexapeptide (Km 11 microM), N alpha-dansyl-N omega-ADP- ribosylarginine methyl ester (Km 12 microM), N alpha-dansyl-N omega-ADP- ribosylarginine (Km 12 microM), N alpha-dansyl-N omega-1,N6-etheno-ADP- ribosylarginine methyl ester (Km 11 microM), and N alpha-dansyl-N omega- GDP-ribosylarginine methyl ester (Km 11 microM) were comparable substrates. N omega-ADP-ribosylarginine (Km 2 mM) was a poor substrate, and the activating enzyme did not catalyze N-glycohydrolysis of N alpha- dansyl-N omega-5'-phosphoribosylarginine methyl ester or N alpha-dansyl- N omega-ribosylarginine methyl ester. 13C NMR of N alpha-tosyl-N omega- ADP-ribosylarginine methyl ester established that the activating enzyme specifically hydrolyzed the alpha-ribosyl-guanidinium linkage. The beta- linked anomer was hydrolyzed only after anomerization to the alpha configuration. We recommend [arginine(N omega-ADP-alpha- ribose)]dinitrogenase reductase N-glycohydrolase (dinitrogenase reductase activating) and dinitrogenase reductase activating glycohydrolase as the systematic and working names for the activating enzyme.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				C. M. Halbleib, Y. Zhang, and P. W. Ludden Regulation of Dinitrogenase Reductase ADP-ribosyltransferase and Dinitrogenase Reductase-activating Glycohydrolase by a Redox-dependent Conformational Change of Nitrogenase Fe Protein J. Biol. Chem., February 4, 2000; 275(5): 3493 - 3500. [Abstract] [Full Text] [PDF]