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Biomedical subjects

V Mutt

Publications and source records attributed to V Mutt.

At least 181 records · Page 10Linked to original sources
PubMed1978

Cholecystokinin (pancreozymin). 4. Synthesis and properties of a biologically active analogue of the C-terminal heptapeptide with epsilon-hydroxynorleucine sulfate replacing tyrosine sulfate.

The influence of tyrosine O-sulfate, the 27th residue in the sequence of cholecystokinin (pancreozymin) (CCK-PZ), on the contraction of gall bladder of guinea pigs and on the release of amylase in isolated pancreatic cells of the same animal was studied with an analogue of the biologically active C-terminal heptapeptide, CCK-PZ-(27--33). In the new analogue, tyrosine O-sulfate was replaced by epsilon-hydroxynorleucine O-sulfate. The synthetic peptide was found a full agonist in these tests, not quite as potent as the unaltered heptapeptide, but much more active than the previously prepared and studied serine O-sulfate containing analogue. Thus, the distance of the sulfate ester group from the peptide backbone has a major influence on the biological activity of CCK-PZ.

Amino Acid Sequence↗
PubMed1978

Chemical determination of polypeptide hormones.

The presence or absence of peptide hormones in tissue extracts may in certain cases be demonstrated by exposing the extracts to conditions under which characteristic fragments of the polypeptide molecule in question are formed and then analyzing for such fragments. An approximate quantitation of the hormones may also be achieved thereby. In the present work the COOH-terminal fragments of polypeptides containing characteristic alpha-amide groups were released enzymatically and then converted into the fluorescent dansyl derivatives, which were identified by thin-layer chromatography. In this way the presence of secretin, cholecystokinin, and the vasoactive intestinal peptide in concentrates of porcine intestinal extracts were demonstrated by their COOH-terminal amide fragments: valine (or leucylvaline) amide, phenylalanine amide, and asparagine (or leucylasparagine) amide, respectively. The analytical methodology used in the present study may also be useful in devising simple and reliable chemical assay methods for the isolation of already known polypeptides and in the isolation of previously uncharacterized polypeptides from natural sources.

Amides↗
PubMed1978

A gastrin releasing peptide from the porcine nonantral gastric tissue.

This paper presents evidence for the existence in extracts from porcine non-antral gastric tissue of a peptide capable of causing substantial rises of plasma immunoreactive gastrin levels in a dose dependent manner and of stimulation of gastric acid and pepsin secretion. Obtained data show that the peptide is basic and that its gastrin releasing properties are at least partially resistant to atropinisation and beta-receptor blockade. Antrectomy almost eliminates the rise in plasma IRGa when the peptide is administered. The possible relationship of this peptide to amphibian bombesin is discussed.

Animals↗
PubMed1976

Further investigations of intestinal hormonal polypeptides.

Attempts are described to identify additional polypeptides of hormonal nature in a concentrate of intestinal polypeptides shown previously to contain secretin, cholecystokinin-pancreozymin (CCK), motilin, gastric inhibitory polypeptide (GIP), vasoactive intestinal polypeptide (VIP), enteroglucagon and chymodenin. The probable amino acid sequence of a variant form of CCK is disclosed. The possibility of using characteristic fragments of polypeptides for the quantitation of the polypeptides themselves in crude preparations is briefly discussed.

Amino Acid Sequence↗
PubMed1976

A fraction isolated from porcine upper small intestine stimulating pepsin secretion in the cat.

The preliminary purification of a material, apparently distinct from any hitherto isolated gastrointestinal hormone, with pepsin release stimulating activity in the cat is described. This material has shown no inhibitory effect on pentagastrin-stimulated secretion of acid, no effect of its own on gastric acid secretion and antral motility, and only a weak stimulatory effect on pancreatic secretion of bicarbonate.

Animals↗
PubMed1970

Polypeptide with broad biological activity: isolation from small intestine.

A polypeptide, which has potent and diverse biological action-including systemic vasodilation, hypotension, increased cardiac output, respiratory stimulation, and hyperglycemia-was isolated from the small intestine of the hog. The peptide has 28 amino acid residues and is chemically distinct from the kinins, "substance P," glucagon, and secretin.

Amino Acids↗