A Kinetic Study of the Imidazole Grouips of Chymotrypsinogen, Chymotrypsin, and Some Derivatives, Using the Temperature-Jump Method

Evidence for an Intermediate in the Acetylation Reaction of Acetylcholinesterase*

“…Simultaneous involvement of two histidines could still be explained if addition of a proton to one drastically altered the pK of the other. The histidines in chymotrypsin would then have to behave abnormally in acid-base titration, whereas their ionization is apparently normal (Marini and Wunsch, 1963;Yapel and Lumry, 1964). Therefore, simultaneous participation must be ruled out.…”

Biochemical Analysis

“…Surface potentials of protein solutions were measured by a rapid flow technique (163) and a stopped-flow microcalorimeter for fast-reaction measurements was described (37). Temperature jump kinetic studies on the binding of imidazole by sperm whale metmyoglobin (7, 124) and of the imidazole groups of chymotrypsinogen, chymotrypsin, and some derivatives (532) were reported. MISCELLANEOUS Three significant reviews were noted, namely polarimetric analysis of protein structure (405), the oxygen-flask method (302), and phase solubility techniques (222).…”