No abstract

A protein with pancreastatin-like immunoreactivity has been isolated and purified from liver metastasis of a patient with insulinoma. NH,-terminal residue analysis, in conjunction with the use of antibodies that are specific for the C-terminal amide peptide of porcine pancreastatin, identified this protein as a 186-amino-acid protein corresponding to human chromogranin A-116-301 (the fragment corresponding to the positions from 116 to 301 of human chromogranin A). Digestion of this protein with trypsin yielded a 48-amino-acid peptide with the retention of full pancreastatin activity. Serum from patient with insulinoma contains a peptide specie(s) that comigrates with the 48-amino-acid pancreastatin, suggesting that this peptide might be a physiologically important circulation form of pancreastatin in humans.A sensitive radioimmunoassay was established using antibody developed against a synthetic 29-amino-acid peptide amide of pancreastatin. Immunocytochemical staining revealed that a major population of human pancreatic islet cells were immunoreactive to the antiserum but with varying intensity of staining. Pancreastatinlike immunoreactivity was not observed in exocrine acinar cells.Pancreastatin (PS), a 49-residue peptide amide, was first isolated from porcine pancreas by Tatemoto et al. in 1986 [l] using an analytical tool specific for the C-terminal amide [2]. This peptide has been shown to inhibit glucose-induced insulin release from the isolated perfused pancreas [3]. Porcine pancreastatin shows striking sequence similarity to a part of bovine chromogranin A [4 -81, a protein normally present in the secretory granules of endocrine and neuronal cells [9]. In 1987, Konecki et al. [lo] proposed that the amino acid sequence of human pancreastatin (hPS) is a 52-residue peptide amide (hPS-52), deduced from the gene structure of human chromogranin A since this gene contained a sequence (positions 250 -31 0) identical to porcine pancreastatin. Recently, the amino acid sequence of rat pancreastatin was also deduced from the gene structure of chromogranin A [I 11. Sekiya et al. reported the isolation of a 29-residue peptide (hPS-29) related to human pancreastatin, from a pancreatic glucagonoma [12, 131 and showed that this peptide was identical to a portion of the cDNA-derived sequence of human chromogranin A. In order to clarify the biological functions of pancreastatin and its relationship with human chromogranin A, it will be necessary to isolate and characterize human pancreastatin. Re- cently, Iacangelo et al. showed that porcine chromogranin A is the precursor of porcine pancreastatin [I41 and Schmidt et al. reported the isolation and amino acid sequence analysis of tumor-derived peptides related to human pancreastatin or chromogranin A [15]. These peptides, consisting of 29 and 92 amino acid residues, respectively, are identical to the Cterminal part of human chromogranin A.In this paper, we report the isolation and characterization of a 186-residue polypeptide amide with pancreastatin-like immunoreactiv...

A 52-and a 29-residue peptide amide corresponding to human pancreastatin and one of its fragments were synthesized by the Fmoc-based solid phase techniques (Fmoc = fluoren-9-ylmethoxycarbonyl), and a new amide precursor reagent, 3-(cx-Fmoc-amino-4-methoxybenzyl)-4-methoxyphenylpropionic acid, was employed in combination with thioanisole-mediated trimethylsilyl bromide deprotection; the synthetic peptides significantly inhibited protein output, but not juice flow or bicarbonate output from rat pancreas.

We collected non-salted Douchi from Yunnan Province, China, and isolated the dominant bacteria for the production of Natto. We identified the most predominant bacteria as Bacillus subtilis, called it KFP 2.-. The toughness of Natto made by us with this strain was about .*ῌ of commercial Natto. Formol nitrogen content and relative viscosity of Natto made by us with B. subtilis KFP 2.-was about-*ῌ and /*ῌ, respectively, of those of the commercial Natto. Organoleptic assessment revealed that the stickiness of Natto made by us was weaker than commercial Natto, but that the former was softer. The appearance, clack of soybean and toughness were considered good. The softer Natto will be useful for individuals who experience di$culty swallowing or in mastication.