Notes on Pepsin

Action of Pepsin on Gelatin

Crystalline Pepsin

The decrease in protein nitrogen and in the activity of solutions of crystalline pepsin at pH 1.8 and 45 degrees C. has been determined. The decrease in activity, as measured with eleven different methods, is in exact proportion to the decrease of protein nitrogen of the solution. The measurements were continued until less than 5 per cent of the original protein remained. These results indicate...

Crystalline Pepsin Iii. Preparation of Active Crystalline Pepsin from Inactive Denatured Pepsin By

The results (1) of the experiments with crystalline pepsin isolated from crude pepsin preparations indicated that the material is a pure substance and that the proteolytic activity is a property of the protein molecule itself and is not due to the presence of a separate non-protein impurity. No indication of the presence of a more highly active nonprotein molecule was obtained in the solubility...

Fluorescence studies on the active sites of porcine pepsin and Rhizopus-pepsin.

Fluorescence studies on the interaction, with porcine pepsin, of oligopeptides bearing a mansyl (Mns, 6-(N-methylanilino)-2-naphthalenesulfonyl) or dansyl (Dns, 5-dimethylaminonaphthalene-1-sulfonyl) group at the NH2 or COOH terminus have provided further evidence showing that the probe group is drawn into the extended active site largely as a consequence of the specific binding of the peptide ...

Notes on Lactuca saligna in Iran

In the identification process of weed materials available in "IRAN" herbarium, a specimen belonging to the genus Lactuca (Asteraceae) had the following characteristics: Plant annual, many stemmed from base; stem erect-slightly procumbent, slender, glabrous, whitish and leafy. Basal leaves dried; stem leaves ca. 7 × 0.5 cm, glabrous, linear-lanceolate, entire at margin, sessile, auriculate, auri...