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 Bobsein, B. R. Articles by Myers, R. J. Search for Related Content PubMed PubMed Citation Articles by Bobsein, B. R. Articles by Myers, R. J. Social Bookmarking                      What's this?

J. Biol. Chem., Vol. 256, Issue 11, 5313-5316, Jun, 1981

113Cd NMR in binary and ternary complexes of cadmium-substituted horse liver alcohol dehydrogenase

BR Bobsein and RJ Myers

The 113Cd NMR has been observed for Cd(II)-substituted horse liver alcohol dehydrogenase (LADH) and its complexes with coenzymes and several substrate analogs. Compared to free enzyme, the catalytic Cd(II) resonance is shielded by 41--41 ppm in both LADH-NADH and LADH- NAD+. In ternary complexes of LADH-NAD+ with either trifluoroethanol or pyrazole, this resonance narrows and is deshielded by 75 ppm. The LADH- NADH-butyramide complex gives only 3 ppm of deshielding relative to the LADH-NADH resonance. At pH = 10.3, the catalytic resonance of unbound LADH is broadened and slightly deshielded. No other resonances are dependent upon pH in the range 8--10. These data are the most consistent with a second sphere coordination of the substrate analogs to the catalytic metal ion. The observed difference between complexes of the alcohol analogs and the aldehyde analog would then be explained as the presence of a hydroxide versus a water molecule, respectively, in the first coordination sphere. The data also show that the pKa of the coordinated water on the Zn(II) in the native LADH is close to 9.2 as previously assumed, whereas the pKa of the Zn(II)-bound water in the LADH-NAD+ complex is most likely greater than 9 and not 7.6 as previously assumed.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				L. Myers, M. Terranova, A. Ferentz, G Wagner, and G. Verdine Repair of DNA methylphosphotriesters through a metalloactivated cysteine nucleophile Science, August 27, 1993; 261(5125): 1164 - 1167. [Abstract] [PDF]

				P. D. Ellis Cadmium-113 Magnetic Resonance Spectroscopy Science, September 16, 1983; 221(4616): 1141 - 1146. [Abstract] [PDF]