A solution of chymotrypsin on slight hydrolysis undergoes an irreversible change into new proteins, two of which are enzymes and have been isolated in crystalline form. The new crystalline enzymes, called beta and gamma chymotrypsins, differ from the original chymotrypsin as well as from each other in many physical and chemical respects, such as molecular weight, crystalline form, solubility, a...

Platelet function and the interaction of platelets with human fibrinogen have been studied following degradation of membrane glycoproteins by chymotrypsin. Washed human and rabbit platelets were treated with a-chymotrypsin (1-50 U/mI), which cleaved glycopeptides from membrane glycoproteins without causing aggregation or release of granule contents. Chymotrypsin removed a large percentage of th...

The preparation of a new stable and active form of chymotrypsin is described. The enzyme possesses threonine-147 instead of alanineas the NH&erminal group of the C chain and has been called ai-chymotrypsin. The conformational transition that affects chymotrypsins at alkaline pH was investigated and compared with that of 01and &chymotrypsins by studying the kinetic constants and their pH depende...

Specimens of meconium and random stools were collected sequentially from 25 healthy newborn babies over the first 8-14 days of life. The stool chymotrypsin concentrations increased from birth to a maximum at 4 days of age and then fell again over the next four days. The lowest individual stool concentrations either side of the four day peak were both, coincidentally, 120 micrograms/g stool. In ...

Our understanding of enzyme catalysis has advanced steadily since x-ray diffraction results gave the first detailed information about the architecture of an enzyme molecule 10 years ago. The mechanism of chymotrypsin is probably understood in more detail than any other enzyme a t the present time. As enzymes go, it is a very simple one, and it has proved accessible to study by a wide range of d...