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Biomedical subjects

L T SKEGGS

Publications and source records attributed to L T SKEGGS.

At least 19 recordsLinked to original sources
PubMed1964

THE PRESENCE OF RENIN ACTIVITY IN BLOOD VESSEL WALLS.

The preparation, of an extract of hog blood vessels and organs containing renin activity has been described. The extract hydrolyzes natural or synthetic renin substrate to form a vasopressor material. This reaction could not be distinguished from the hydrolysis of renin substrates by kidney renin. The activation energy, effect of substrate concentration on velocity, inhibition by antirenin, and pH optimum of the extract and of kidney renin are the same. Renin activity is found in the adventitia and media of the aorta, the liver and, to a lesser extent, in other vascular organs.

Angiotensins↗
PubMed1963

The purification and partial characterization of several forms of hog renin substrate.

Hog renin substrate has been separated into three major (A, B, and C) and two minor forms (D and E) by DEAE cellulose chromatography. Two of the major forms (B and C) have been further fractionated into two additional types (1 and 2) by countercurrent distribution. The purification of substrates A, C(1), and C(2) has been completed. Analysis shows that all three are glycoproteins with molecular weights of about 57,000, and have similar amino acid compositions. Differences exist in the sialic acid, glucosamine, and neutral hexose content, which may account for different physical properties. All the forms of the substrates are attacked by renin at similar rates, and appear to yield the same angiotensin I.

Amino Acids↗
PubMed1958

The synthesis of a tetradecapeptide renin substrate.

A tetradecapeptide renin substrate having a biological activity comparable to the natural product and similar chemical properties has been synthesized by means of the carbobenzyloxyl azide and mixed anhydride methods.

Angiotensinogen↗
PubMed1957

The preparation, purification, and amino acid sequence of a polypeptide renin substrate.

A purified preparation of a polypeptide renin substrate prepared by tryptic degradation of the protein renin substrate has been analyzed by the fluorodinitrobenzene method and after degradation with renin, carboxypeptidase, and phenylisothiocyanate, has been found to possess the amino acid sequence; asp-arg-val-tyr-ileu-his-pro-phe-his-leu-leu-val-tyr-ser. The first 10 of these amino acids constitutes hypertensin I which is released by cleavage of the leucyl-leucine bond by renin. The remaining 4 amino acids, leu, val, tyr, ser, apparently link hypertensin I to the protein renin substrate.

Amino Acid Sequence↗
PubMed1956

The amino acid composition of hypertensin II and its biochemical relationship to hypertensin I.

Preparations of hypertensin II, obtained from the treatment of hypertensin I by the action of the hypertensin converting enzyme of plasma and purified by countercurrent distribution, were quantitatively analyzed for their amino acid content. Chromatography on ion exchange columns showed the presence of equimolar amounts of aspartic acid, proline, valine, isoleucine, tyrosine, phenylalanine, histidine, and arginine. Hypertensin I was found to contain one mole of leucine and one mole of histidine in addition to the amino acids of hypertensin II. These two amino acids were isolated from the conversion products of hypertensin I and identified as the peptide histidylleucine. Carboxypeptidase digestion of hypertensin I showed the carboxyl terminal sequence of amino acids to be residue-phenylalanyl-histidylleucine. Similar studies of hypertensin II demonstrated residue-phenylalanine. It was concluded that the conversion of hypertensin I by the plasma hypertensin converting enzyme involved hydrolysis of the phenylalanyl-histidine bond to form hypertensin II and histidylleucine. The further removal by carboxypeptidase of phenylalanine from hypertensin II destroyed all of the vasoconstrictor activity.

Amino Acids↗
PubMed1956

The amino acid sequence of hypertensin. II.

The amino acid sequence of horse hypertensin II has been determined by the use of chymotrypsin, the fluorodinitrobenzene method, and stepwise phenylisothiocyanate degradation. The results indicate that the amino acids of hypertensin II are arranged in the following order: asp-arg-val-tyr-iso-hist-pro-phe.

Amino Acid Sequence↗