Biophysical Journal 1: 437-444 (1961)
© 1961 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services 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 Google Scholar Google Scholar Articles by Samuels, A. J. Search for Related Content PubMed PubMed Citation Articles by Samuels, A. J.

Immunoenzymological Evidence Suggesting a Change in Conformation of Adenylic Acid Deaminase and Creatine Kinase during Substrate Combination

ABSTRACT

The kinetics of inhibition of 5'-adenylic acid deaminase and creatine-ATP transphosphorylase by their respective antibodies are studied and rate constants of combination are ascertained. It is shown that the single substrate 5'-adenylic acid (AMP) of deaminase "protects" the enzyme against antibody inhibition. However, phosphate, a competitive inhibitor of the highly specific deaminase, enhances combination with antibody. With creatine kinase, however, addition of either of the substrates, alone or in combination with the required magnesium, each of which separately bind to the enzyme, does not prevent inhibition of the enzyme by its antibody. However, the "working" enzyme combined with all substrates is "protected" against antibody inhibition.