Keratins are the proteins of epidermal and skeletal tissues which are insoluble in the usual protein solvents, not digested by trypsin or pepsin, and high in cystine content. Such a definition intentionally excludes fibroin, the major protein of silk. It will be shown in this paper that keratins can be converted into proteins soluble in alkali or acid, with a definite optimum pH of flocculation...

A novel sensitive and relatively selective kinetic method is presented for the determination of V(V), based on its catalytic effect on the oxidation reaction of Ponceau Xylydine by potassium bromate in presence of 5-sulfosalicylic acid (SSA) as activator. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of Ponceau Xylydine at 640 nm between 0.5 to 7 min ...

In 1928, Schmidt (1) first described the presence of 5’-adenylic acid deaminase in muscle. He succeeded in separating this enzyme from adenosine deaminase and in isolating inosinic acid and ammonia as products of the reaction. He also reported that it specifically deaminated 5’-adenylic acid. In 1947, Kalckar (2) described two methods for the preparation of this enzyme and introduced a spectrop...

CLINICAL CHEMISTRY, Vol. 25, No. 4, 1979 643 fled by adding a precalibrated CSF protein scale, generated by use of a diluted commercial lyophilized qualitycontrol serum. We investigated the validity of using lyophilized materials to construct a precalibrated scale for this nephelometric assay. We found that analyses of serial dilutions of quality-control sera showed a linear relationship betwee...