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V Mutt

Publications and source records attributed to V Mutt.

204 records · Page 12Linked to original sources

Production of a biologically active variant form of recombinant human secretin.

A biologically active variant form of recombinant human secretin was produced using a gene fusion system designed to facilitate the purification of the protein. The fusion protein was recovered from the culture medium of Escherichia coli by IgG affinity chromatography, and recombinant secretin was released by cyanogen bromide treatment. A novel approach involving addition of a C-terminal Gly-Lys-Arg extension, was used to overcome the lack of amidation of recombinant proteins in Escherichia coli. The biological activity of the recombinant variant of secretin was at least 80% of the porcine secretin standard.

Amino Acid Sequence↗

Influence of vasoactive intestinal polypeptide (VIP) on splanchnic and central hemodynamics in healthy subjects.

The influence of VIP, a potent vasodilator, on central hemodynamics, splanchnic blood flow and glucose metabolism was studied in six healthy subjects. Teflon catheters were inserted into an artery, a femoral vein and a right-sided hepatic vein. A Swan-Ganz catheter was introduced percutaneously and its tip placed in the pulmonary artery. Determinations of cardiac output, systemic, pulmonary arterial and hepatic venous pressures as well as splanchnic blood flow were made in the basal state and at the end of two consecutive 45 min periods of VIP infusion at 5 and 10 ng/kg/min, respectively. Arterial blood samples for analysis of glucose, FFA, insulin and glucagon were drawn at timed intervals. VIP infusion at 5 ng/kg/min resulted in an increase in cardiac output (55%) and heart rate (25%) as well as a reduction in mean systemic arterial pressure (15%) and vascular resistance (45%). With the higher rate of VIP infusion heart rate tended to rise further while cardiac output and arterial pressure remained unchanged. At 15 min after the end of VIP infusion the above variables had returned to basal levels. Splanchnic blood flow and free hepatic venous pressure did not change significantly. Arterial concentrations of glucose, FFA, insulin and glucagon increased during VIP infusion. At 15 min after the end of infusion the glucose levels were still significantly higher than basal (20%). Net splanchnic glucose output did not change in response to VIP infusion. It is concluded that VIP exerts a potent vasodilatory effect resulting in augmented cardiac output and lowered systemic blood pressure and vascular resistance.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Variant forms of galanin isolated from porcine brain.

In a peptide concentrate, prepared from acid extracts of porcine brain, several galanin-like immunoreactive peptides were detected and two of these were purified. Characterization of the peptides by sequence analysis, mass spectrometry, and capillary zone electrophoresis identified them as a N-terminally nine residue elongated form of galanin, preprogalanin(24-61) amide, and as an N-terminally four residue truncated form of galanin corresponding to preprogalanin(37-61) amide. The former finding suggests that the removal of the signal peptide in preprogalanin occurs by enzymatic cleavage between glycine-23 and leucine-24. The presence of truncated galanin might refer to a mechanism, where galanin is inactivated by removal of functionally important amino acid residues from the N-terminus.

Amino Acid Sequence↗

Characterization of porcine gastric galanin.

The presence of a peptide capable of producing powerful contractions of rat small intestinal smooth muscle was detected in chromatographic fractions derived from porcine gastric corpus extracts. The pharmacological characteristics of this entity suggested that it might be galanin and on its purification to homogeneity, amino acid composition and sequence analysis demonstrated the identify of the gastric and intestinal forms of galanin. The presence of galanin in the gastric corpus tissue and its ability to affect gastric smooth muscle activity, gastrin release, and gastric acid secretion suggest potential important physiological roles for galanin in the stomach.

Amino Acid Sequence↗

Pancreastatin, a novel pancreatic peptide that inhibits insulin secretion.

In mammalian tissues the C-terminal amide structure has been found to occur only in neuroactive or hormonally-active peptides. About half known neuropeptide and peptide hormones have this unique chemical feature. Using a chemical detection method, a search for previously unknown peptides that possess the C-terminal amide structure in extracts of brain and intestine was carried out and a number of novel neuropeptides and hormonal peptides, designated neuropeptide Y, PHI, peptide YY, galanin and neuropeptide K were isolated. We recently performed a similar search in porcine pancreas and found a high concentration of a peptide having a glycine amide at its C-terminus. Here we report the isolation, primary structure and biological activity of this novel peptide. The 49-residue peptide strongly inhibits glucose-induced insulin release from the isolated perfused pancreas and was therefore named pancreastatin. It may be important in the regulation of insulin secretion and in the pathogenesis and treatment of diabetes mellitus.

Amino Acid Sequence↗