Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-Terminal analysis of purified buffalo thyroglobulin by the fluorodinitrobenzene method of Sanger yielded about 1.5 moles of DNP-glutamic acid per mole of buffalo thyroglobulin. No water-soluble DNP-amino acid was detectable as N-terminal. The presence of glutamic acid has been confirmed by Edman degradation and characterization of the PTH-amino acid in different solvent systems, and also after regeneration of free amino acid from PTH-amino acid in butanol-acetic acid-water (4:1:5, v/v) system. This is in contrast to the occurrence of aspartic acid or asparagine as N-terminals for several other mammalian thyroglobulins.
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PMID:N-terminal groups of buffalo thyroglobulin. 235 50

Porcine pancreatic alpha-amylase I, a single 496 residue long polypeptide chain, contains 5 disulfide bridges and 2 free -SH groups. The conditions for specific blocking of native amylase either with radioactive N-ethyl maleimide or with labeled iodoacetic acid were determined. Under these conditions 2 moles of blocking reagent are incorporated per mole of amylase. [14C]-S-succinimido amylase was cleaved by CNBr and the resulting peptides were purified. Only one of them the CNBr 2 + 3 peptide (178 residues) was found labeled. Ts1 a 33-residue peptide containing the whole radioactivity was purified from the tryptic digest of this large fragment. After reduction and carboxymethylation Ts1A, (22 residues) was obtained which contains 2 moles of succinyl-Cys and one mole of CM-Cys per mole of peptide. Chymotryptic digestion of Ts1A yielded 2 equally labeled peptides: C1 (16 residues) and C2 (6 residues). Automated sequencing of both peptides and counting of the PTH-amino acids shows that the free cysteines are only 15 residues apart in the sequence.
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PMID:Localization of the two free thiol groups in the porcine pancreatic alpha-amylase I sequence. 618 59

Fresh parathyroid gland homogenates and fractions thereof were analyzed for their content of PTH and carboxyl-terminal fragments of the hormone. The tissue proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then extracted from gel fractions for RIA. Native PTH and PTH-(37-84) were used as standards to mark the migration positions of these peptides in the gels. The RIA for carboxyl-terminal hormone fragments used PTH-(37-84) as radioiodinated tracer and responded equally on a molar basis to either PTH or PTH-(37-84), making possible quantitative evaluation of both peptides in one assay after their separation. The results indicated that tissue homogenates contain 0.3-0.5 PTH-(37-84) moleq for each mole of PTH. Particulate fractions of the homogenates contained 0.15-0.3 moleq of fragment/mol PTH, while the high speed supernatant fraction of the homogenate contained about 2 moleq of fragment/mol PTH. When the experiments were performed using homogenization and fractionation buffers that contained numerous protease inhibitors, the ratios of carboxyl-terminal PTH fragment to intact hormone were not decreased, indicating that the hormone fragments were not produced during tissue processing. In addition, PTH added to tissue homogenates was not degraded during subsequent manipulations. The results demonstrate that fresh bovine parathyroid tissue contains substantial levels of carboxyl-terminal PTH peptide fragments, which can be measured by RIA after separation from PTH and other hormonal species. The data support the hypothesis that hormone fragments reside in regions of the cell different from those that contain PTH.
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PMID:The content of carboxyl-terminal fragments of parathormone in extracts of fresh bovine parathyroids. 682 2

Cell aggregates of bovine parathyroid tissue were prepared by limited collagenase digestion and placed in culture in Weymouth's MB752/1 (calcium = 3.3 mg/100 ml) containing 5% fetal bovine serum and supplemented with insulin alone, or insulin, hydrocortisone, transferrin and epidermal growth factor. Only insulin was required for the maintenance of PTH secretion over a 9-day period. The cell aggregates spread to form monolayer in 3-5 days. The majority of the cells in monolayer were polygonal with well-defined borders. Nuclei were round and the cytoplasm was free of vacuoles. Cell cultures responded to secretory stimulation by low calcium or by isoproterenol with increases in the secretion of PTH and SP-1. At low calcium, about 18% of both the cellular PTH and SP-1 was secreted per hour, and up to 50% of the cell content of these proteins was released per hour upon stimulation by isoproterenol and low calcium combined. The responses to calcium and isoproterenol decreased as a function of time in culture, and calcium responses often disappeared completely by 10 days of culture. When cells were cultured in medium containing a higher (5 mg%) than standard concentration of calcium between days 3-6 of culture, the degree of secretory inhibition attainable with high calcium was greater than that of cells cultured in the standard medium. When secreted hormonal peptides were separated by SDS-gel electrophoresis prior to RIA, it was found that the secretion of intact hormone was sensitive to calcium. For every molecule of PTH secreted into the medium, 1.5-2 mole-equivalents of carboxyl fragments were also released. Calcium control of fragment release was not as stringent as that of PTH release.
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PMID:Primary monolayer cell culture of bovine parathyroids: effects of calcium, isoproterenol and growth factors. 686 97