The Action of Ninhydrin on the Enzymatic and Actincombining Properties of Myosin

Abstract

Ninhydrin at 5 I-tM per mg. myosin produces 90 per cent. inhibition of luyosin-ATP-ase at pH 9.0 in 3 hours at 5°C. At pH 7.0 the same inhibition is produced by 35 I-tM ninhydrin per mg. myosin. This inhibition is reversed by cysteine, the release being complete after one hour's treatment of the myosin by ninhydrin, but incomplete, except with very high cysteine concentrations, after three hours' treatment of the myosin. Other amino acids did not release the inhibition produced by ninhydrin.