Testosterone has been detected in whole human saliva. Levels averaged (+/- SE) 295 +/- 36 and 195 +/- 25 pg/ml in adult males and females, respectively, and usually were undetectable in children. In adult males, the excretion of testosterone in saliva appeared to follow a circadian rhythm.

Erythrocyte membranes prepared by three different procedures showed (Mg2+ + Ca2+)-ATPase activities differing in specific activity and in affinity for Ca2+. The (Mg2+ + Ca2+)-ATPase activity of the three preparations was stimulated to different extents by a Ca2+-dependent protein activator isolated from hemolysates. The Ca2+ affinity of the two most active preparations was decreased as the ATP concentration in the assay medium was increased. Lowering the ATP concentration from 2 mM to 2-200 microM or lowering the Mg:ATP ratio to less than one shifted the (Mg2+ + Ca2+)-ATPase activity in stepwise hemolysis membranes from mixed "high" and "low" affinity to a single high Ca2+ affinity. Membranes from which soluble proteins were extracted by EDTA (0.1 mM) in low ionic strength, or membranes prepared by the EDTA (1-10 mM) procedure, did not undergo the shift in the Ca2+ affinity with changes in ATP and MgCl2 concentrations. The EDTA-wash membranes were only weakly activated by the protein activator. It is suggested that the differences in properties of the (Mg2+ + Ca2+)-ATPase prepared by these three procedures reflect differences determined in part by the degree of association of the membrane with a soluble protein activator and changes in the state of the enzyme to a less activatable form.

Affinity chromatography of chymotrypsin-like proteases on a column of Sepharose–4-phenylbutylamine (PBA) has been developed. Sepharose–PBA (Sepharose–NH∙[CH2]4∙C6H5) has been shown to selectively adsorb chymotrypsin α and B from weakly alkaline solutions and to allow to pass through unretarded porcine trypsin, bovine trypsinogen, and chymotrypsin α modified with active-site-directed irreversible inhibitors. Chymotrypsinogen A and bovine trypsin were only slightly retarded whereas a preparation of subtilisin was markedly retarded and separated into two distinct peaks. Sepharose–PBA has been utilized successfully for the selective isolation of chymotryps in-like proteases from extracts of moose pancreas (Alces alces).

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Biotin-mediated ATP-32PPi exchange has been used to assay acetyl-CoA holocarboxylase synthetase. The procedure is a potential alternative to the assay which uses the incorporation of biotin into acetyl-CoA apocarboxylase.