The pyridoxal-5'-phosphate-dependent catalytic antibody 15A9: its efficiency and stereospecificity in catalysing the exchange of the alpha-protons of glycine

FEBS Letters
M M MahonJ Paul G Malthouse

Abstract

13C-NMR has been used to follow the exchange of the alpha-protons of [2-(13)C]glycine in the presence of pyridoxal-5'-phosphate and the catalytic antibody 15A9. In the presence of antibody 15A9 the 1st order exchange rates for the rapidly exchanged proton of [2-(13)C]glycine were only 25 and 150 times slower than those observed with tryptophan synthase (EC 4.2.1.20) and serine hydroxymethyltransferase (EC 2.1.2.1). The catalytic antibody increases the 1st order exchange rates of the alpha-protons of [2-(13)C]glycine by at least three orders of magnitude. We propose that this increase is largely due to an entropic mechanism which results from binding the glycine-pyridoxal-5'-phosphate Schiff base. The 1st and 2nd order exchange rates of the pro-2S proton have been determined but we were only able to determine the 2nd order exchange rate for the pro-2R proton of glycine. In the presence of 50 mM glycine the antibody preferentially catalyses the exchange of the pro-2S proton of glycine. The stereospecificity of the 2nd order exchange reaction was quantified and we discuss mechanisms which could account for the observed stereospecificity.

References

Jan 1, 1992·Annual Review of Biochemistry·S J Benkovic
Oct 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·H C Dunathan, J G Voet
Apr 1, 1966·Proceedings of the National Academy of Sciences of the United States of America·H C Dunathan
Aug 1, 1971·Proceedings of the National Academy of Sciences of the United States of America·M I Page, W P Jencks
Apr 27, 1995·Biochimica Et Biophysica Acta·R A John
Feb 1, 1996·Biochemical Society Transactions·J Paul G MalthouseM M Mahon
Sep 1, 1995·Journal of Biochemistry·H Hayashi
Jan 1, 1996·Advances in Protein Chemistry·E M Driggers, P G Schultz
Nov 29, 1996·The Journal of Biological Chemistry·Svetlana Gramatikova, P Christen
Dec 3, 1996·Biochemistry·L Young, C B Post

Citations

Apr 5, 2002·Chemical Record : an Official Publication of the Chemical Society of Japan ... [et Al.]·P Christen, P K Mehta
Oct 16, 2002·Journal of Immunological Methods·Svetlana GramatikovaP Christen

Related Concepts

Antibody Specificity
Glycine, Monopotasssium Salt
Protons
Pyridoxal Phosphate
Substrate Specificity
Antibodies, Catalytic

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