[Proteinases and their inhibitors in intervertebral discs].

The authors investigated the incidence of proteinases and their inhibitors in bovine intervertebral discs. They proved the presence of proteinases of all basic enzyme classes. In some instances (in the class of cysteine proteinases) a more detailed specification of the present enzymes could be made.

Isolation and some properties of an acid protease from Fasciola hepatica.

A new protease, detected in an extract of Fasciola hepatica, was isolated and partly purified. The pH optimum for the cleavage of denaturated haemoglobin by the enzyme is pH 3.0.

The first step in the activation of chicken pepsinogen is similar to that of prochymosin.

Chicken pepsinogen was incubated at pH2.5 with pepstatin. The zymogen activated itself by a sequential mechanism and an intact peptide derived from residues 1-26 in the protein was released in the first step.

Naturally occurring inhibitors of intracellular proteinases.

The papain inhibitor isolated from chicken egg white inhibits the enzymatic activity of cathepsin B1 and cathepsin C. The inhibitor bears two nonoverlapping reactive sites: one binds cathepsin B1, papain, ficin, and bromelain, the other one cathepsin C. The inhibitor decreases the degree of an immunologic hypersensitive reaction, the so-called Arthus reaction.