It has been shown in previous publications that neither of the cytidylic acid isomers isolated from hydrolysates of yeast ribonucleic acid is oxidized by sodium periodate under conditions in which an unsubstituted Q: ,@-glycol grouping is readily oxidized (1, 2). These results indicate that each compound is phosphorylated in either the 2’ or the 3’ position and eliminate cytidine-5’-phosphate a...

Potter, V. R. & Recknagel, R. 0. (1951). In Phosphorus Metaboli8m, vol. 1, p. 377. Ed. by McElroy, W. D. & Glass, B. Baltimore: Johns Hopkins Press. Potter, V. R., Siekevitz, P. & Simonson, H. C. (1953). J. biol. Chem. 205, 893. Robertson, H. E. & Boyer, P. D. (1955). J. biol. Chem. 214, 295. Sacktor, B. (1953). J. gen. Phy8iol. 36, 371. Schneider, W. C. & Hogeboom, G. H. (1950). J. biol. Chem....

For the study of alkaline phosphatase systems a non-phosphate-containing buffer is required. The buffers in common use for the alkaline pH range are ammonia, borate, glytine and veronal. Ammonia and borate have a retarding effect on the rate of ,enzymic hydrolysis of phosphoric esters. Glycine activates phosphatase when present in very low concentrations (0 1-1 mm), but in the concentrations us...

The present investigation identifies bovine liver mitochondrial NADase (NAD+ glycohydrolase) as a member of the class of bifunctional ADP-ribosyl cyclases/cyclic ADP-ribose hydrolases, known to be potential second messenger enzymes. These enzymes catalyse the synthesis and degradation of cyclic ADP-ribose, a potent intracellular calcium-mobilizing agent. The mitochondrial enzyme utilized the NA...

In order to investigate the relationships between the three-dimensional structure and the enzymic activity of E. coli RNase HI, three mutant proteins, which were completely inactivated by the replacements of three functional residues, Asp10 by Asn (D10N), Glu48 by Gln (E48Q), and Asp70 by Asn (D70N), were crystallized. Their three-dimensional structures were determined by x-ray crystallography....

The enzymic degradation of insoluble polysaccharides is one of the most important reactions on earth. Despite this, glycoside hydrolases attack such polysaccharides relatively inefficiently as their target glycosidic bonds are often inaccessible to the active site of the appropriate enzymes. In order to overcome these problems, many of the glycoside hydrolases that utilize insoluble substrates ...

Since previous investigations have provided evidence that certain proteinases of the trophoblast playa key role in initiation of implantation of the embryo in the uterus, enzymic characterization of endopeptidase activity of rabbit blastocyst extracts was attempted. Recently developed tripeptide p-nitroanilide substrates now allow far the first time quantitative assays of enzyme activities in t...

A series of novel synthetic peptides, containing a C-terminal beta-amino alcohol linked to p-methoxybenzoic acid via an ester linkage, have been prepared and tested as inhibitors against typical members of the serine protease family. For example, the sequences Ac-Val-Pro-NH-CH-(CH2-C6H5)-CH2O-CO-C6H4-OCH3 (I) and Ac-Val-Pro-NH-CH-[CH-(CH3)2]-CH2O-CO-C6H4-OCH3 (II), which fulfil the known primar...