Electrophoretic demonstration of specific enzyme-substrate complex between pepsin and serum albumin. II. Inhibition of complex formation by acetyl-L-tryptophan and fatty acids.

The first paper of this series (1) described an electrophoretic demonstration of a complex between pepsin and bovine serum albumin during the course of the enzymatic hydrolysis of the latter. Several independent lines of evidence were presented that this complex is the Michaelis-Menten complex capable of being activated to give rise to reaction products. This communication reports the results of electrophoretic experiments on inhibition of complex formation between pepsin and bovine serume albumin by acetyl-n-tryptophan and fatty acids. These experiments not only afford further evidence for the specificity of the electrophoretically demonstrable pepsin and bovine serum albumin complex but also have a bearing on the general concepts of proteolytic mechanisms.