Biophysical Journal 72: 858-865 (1997)
© 1997 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 Xie, L. Articles by Schoenberg, M. Search for Related Content PubMed PubMed Citation Articles by Xie, L. Articles by Schoenberg, M.

Graphical Evaluation of Alkylation of Myosin's SH1 and SH2

The N-Phenylmaleimide Reaction

Laboratory of Physical Biology, National Institute of Arthritis, and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
Department of Physiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455 USA

ABSTRACT

Previous assertions about the effect of alkylation of SH1 and SH2 on the myosin high-salt calcium and EDTA ATPases have been summarized, and a simple procedure for obtaining the fractional labeling of SH1 and SH2 after treatment of myosin with alkylating agents has been derived. A simple graphical procedure for illustrating the degree of preference of a particular alkylating agent for SH1 over SH2 has also been developed. The procedures we developed were validated by applying them to two previously studied compounds, 4-(2-iodoacetamido)-TEMPO and 2,4-dinitrofluorobenzine, and then were used to determine a procedure for maximizing the extent of labeling of SH1 alone by N-phenylmaleimide, a compound not previously studied in this manner. It was found that 80% of the SH1 sites could be alkylated without significant alkylation of SH2.