ARTICLE NO 0030 Binding of Acrylonitrile to Parvalbumin

A previous study has shown that acrylonitrile (ACN) has a long half-life in rainbow trout muscle and that [I4C]ACN appears to be bound to a 10,000-Da protein in muscle. The labeled protein was purified from muscle of trout exposed to [I4C]ACN, separated on 20 % SDS-PAGE, and digested for amino acid analysis and sequence analysis. These studies indicated that the labeled protein was the Ca2+-binding protein parvalbumin. Parvalbumin is an important calcium-binding protein thought to be involved in the regulation of calcium levels in various parts of the body ranging from neurons to fast-twitch muscle contractions. To study the reaction between parvalbumin and [I4C]ACN, frog parvalbumin was incubated with [I4C]ACN in vitro under various conditions. These studies indicated that the maximum labeling occurred at 1 nmol/nmol parvalbumin and at pH 7. Amino acid analysis of the labeled protein indicated that the labeled amino acid was probabl