Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A standard immunofluorescent method was modified for the staining of leptospires in formalin fixed, paraffin embedded tissues. Routine histologic sections were deparaffinized and treated with pepsin prior to staining. Pepsin treatment greatly enhanced subsequent staining of leptospires in naturally infected bovine and porcine tissues as well as in artificially infected tissues. Leptospires in naturally infected bovine tissues were usually undetectable in untreated sections but clearly visible in stained pepsin-treated sections. Naturally infected porcine kidney usually contained high levels of leptospiral antigen which could be stained without prior pepsin treatment. However, pepsin treatment of porcine tissues greatly increased the amount of leptospiral antigen detectable and made individual leptospires more conspicuous. The staining method could employ a single antiserum for the staining of leptospires from 13 serogroups. Also, leptospires could be stained in tissues stored in formalin for more than 14 months and in 26-year-old paraffin embedded tissues.
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PMID:Immunofluorescent staining of leptospires in pepsin treated histologic sections. 309 81

Duodenal ulcer therapy with H2 antagonists initially aimed to control acid secretion throughout the 24-h period, but recently nighttime suppression has been advocated. The effect of single nighttime regimens of cimetidine 400 mg BID, cimetidine 800 mg HS, ranitidine 150 mg HS, and placebo on 24-h intragastric acidity, nocturnal acid output, and pepsin secretion were studied in four healthy volunteers and four patients with healed duodenal ulcer. A nonrandomized dose of cimetidine 1200 mg HS was also studied. For all four treatments, daytime (0730-2230 h) intragastric acidity was reduced by 4-30% in the normals and by 10-44% in the duodenal ulcer patients (NS), while 24-h intragastric acidity was reduced by 44-46% and 40-64%, respectively (p less than 0.05). Reduction in nocturnal acid output was 82-96% in normals and 91-99% in duodenal ulcer, respectively. Pepsin concentration was unaffected by treatment but pepsin concentration was significantly (p less than 0.05) lower in patients than in normals. Mean 24-h gastric acid secretion was reduced by a single nighttime treatment with an H2-receptor antagonist, while nocturnal acid secretion was virtually abolished. H2 antagonists given only at night deserve further clinical evaluation to determine the minimal effective dose and optimal duration of suppression to achieve ulcer healing.
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PMID:A double-blind randomized study comparing different dose regimens of H2-receptor antagonists on 24-hour gastric secretion in normal subjects and duodenal ulcer patients. 309 64

Treatment of mammalian plasmas with pepsin yielded extraordinary quantities of immunoreactive neurotensin (iNT) and methionine5-enkephalin (iENK). The concentrations measured after pepsin-treatment (iNT, 1-5 microM and iENK, 0.1-0.5 microM) were 1-100 thousand times the normal circulating levels of these peptides. The reactions were shown to be time, temperature and pH dependent and to involve the action of pepsin on albumin-like proteins (Mr, ca, 65,000). Pepsin-generated iNT from rat plasma differed from NT since it reacted only with C-terminal directed antisera and eluted earlier than NT during HPLC on mu-Bondapak C-18. Partially purified iNT was active in two bioassays for NT, one which senses changes in vascular permeability to protein after intradermal injection into rats and another which measures release of histamine from isolated rat mast cells. Other biologic activities generated by pepsin-treating plasma included effects on systemic blood pressure in rats and on the contractility of the isolated guinea pig ileum. Some of these, however, were attributable to the formation of angiotensin- and bradykinin-related peptides. Pepsin-generated iENK gave three major peaks during HPLC, one of which (ca, 25%) co-eluted with oxidized ENK and also registered in a radioreceptor assay for opiate-related substances. In addition, this material produced ENK-like effects on the isolated guinea pig ileum and on vascular permeability in rat skin. The precursor-like protein(s) for iENK were distinguished from adrenal proenkephalins since it did not liberate iENK upon digestion with trypsin and carboxypeptidase B. Since pepsin can mimic renin these results suggest the existence of systems in blood (analogous to the renin/angiotensin system) for the generation of biologically active NT- and ENK-related peptides and they also raise the question as to whether other neuropeptides might be found circulating in precursor form(s).
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PMID:Generation of immunoreactive neurotensin(s) and enkephalin(s) by pepsin-treatment of plasma. 310 14

A new staining protocol is described for the immunocytochemical detection of BrdUrd labeled nuclei. Pepsin treatment of ethanol fixed cells or tissue, followed by DNA denaturation at low pH, resulted in increased sensitivity of BrdUrd staining comparable to the thermal denaturation protocol, and decreased background binding. This technique is applicable to cell suspensions, including cultured cells and bone marrow cells. Furthermore, pepsin digestion of ethanol fixed tissue fragments resulted in a high recovery of nuclei in which incorporated BrdUrd could be detected. This possibility, together with the high sensitivity, make this method especially suitable for cell kinetic studies of human solid tumors in vivo.
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PMID:An improved method for the immunocytochemical detection of bromodeoxyuridine labeled nuclei using flow cytometry. 311 95

1. Two pepsins, designated Pepsin I and Pepsin II, were isolated and partially characterized from the stomach of the adult stage salmon Oncorhynchus keta. This stage is developed in a marine environment. 2. One pepsin, designated Pepsin II, was isolated from the stomach of the juvenile stage salmon Oncorhynchus keta. This stage is developed in an estuarine environment. 3. The enzymes were partially purified by ammonium sulfate precipitation, ion exchange chromatography and gel filtration. 4. Pepsins I and II from adults and Pepsin II from juvenile showed proteolytic activity on acid-denatured hemoglobin with a pH optimum of 3. 5. The mol. wt determined by gel filtration on Sephadex G-100 of Pepsin I from juvenile species was found to be 32,000 whereas a value of 27,000 was determined for Pepsin II from juvenile and adult fish. 6. In contrast with Pepsin II, Pepsin I was activated by NaCl. It is suggested that the appearance of NaCl-activated pepsin would represent and adaptive response of the organism to the change from a low to a high salinity environment.
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PMID:Partial purification of pepsins from adult and juvenile salmon fish Oncorhynchus keta. Effect of NaCl on proteolytic activities. 311 85

1. Pepsin II extracted from the gastric mucosa of Scyliorhinus canicula has been characterized and compared to calf chymosin. 2. The kcat and Km of the dogfish enzyme for the synthetic hexapeptide Leu-Ser-Phe(NO2)-Nle-Ala-Leu-OMe have been determined. The kcat/Km ratio is close to that of calf chymosin. Its milk-clotting efficiency is however 21-fold lower than that of calf chymosin. 3. The proteolytic activity against haemoglobin is optimal at pH 2.5. It clots the milk up to pH 6.8. 4. The dogfish pepsin II shows relatively better activity at low temperatures than calf chymosin.
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PMID:Characterization of a chymosin-like pepsin from the dogfish Scyliorhinus canicula. 312 28

The effects of enzymatic digestion on the iron-solubilizing properties of chicken muscle were examined. A water-soluble extract, an acid-soluble extract, and an acid-insoluble fraction were subjected to a simulated gastrointestinal digestion using pancreatin and/or pepsin: The solubility of added Fe was significantly affected only by the acid-insoluble fraction and increased linearly as pepsin digestion progressed from 0 to 4 h. A maximum was reached when this treatment was followed by a 1-h pancreatin digestion. Pepsin digestion products with molecular weight (MW) less than 10,000 solubilized significantly more Fe than those with MW greater than or equal to 10,000. In contrast pancreatin digestion products of MW less than 10,000 were not effective Fe-solubilizing agents. The influence of chicken breast muscle on added Fe solubility appears to be related to the production of digestion intermediates that can act as ligands in the formation of soluble Fe complexes.
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PMID:Solubility of inorganic iron as affected by proteolytic digestion. 312 41

Particle counting immunoassay is based on latex agglutination, the reaction being measured by instrument counting of the particles remaining unagglutinated. Most interference which generally affects latex agglutination can be avoided by pepsin digestion of the sample, provided the antigen (Ag) of interest resists pepsin, which is the case of the hepatitis B surface antigen (HBsAg). Pepsin treatment has the additional advantage of inactivating antibodies and so releasing the Ag from immune complexes. We have set up an assay of HBsAg, proceeding in a prototype of Impact Instrument (Acade Diagnostic Systems, Belgium) at a rate of 60 samples.h-1 and a total running time of 2 or 4 h. This assay was compared with Abbott radioimmunoassay (RIA) in 706 consecutive patients (A) and 31 selected sera for which values close to the cut-off had been obtained by RIA (B). In A, 38 sera were found positive and 668 negative by both methods. In B, RIA after neutralization classified the samples as positive (n = 14), negative (n = 14), or dubious (n = 3). Complete agreement between latex and RIA was achieved for nine positive, 12 negative, and two dubious samples. Of five RIA-positive samples, two were classified as latex-negative and three as dubious in the latex assay. One sample dubious in RIA was found latex-positive and two RIA-negative samples were found, respectively, latex-positive and dubious; when retested after pepsin digestion, the first of them became RIA-positive.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Immunoassay of hepatitis B surface antigen by particle counting after pepsin digestion. 312 14

Pepsin-catalyzed transpeptidation was studied by high resolution 75 MHz 13C nuclear magnetic resonance spectroscopy. Enrichment with 13C at the carbonyl carbons of the substrates Leu-Tyr-NH2 and Leu-Leu-NH2 facilitated detection and identification of the transpeptidation and hydrolysis products of enzymic action. Porcine pepsin was found in each case to synthesize and release the tetrapeptide Leu-Leu-Leu-Leu as the primary product of transpeptidation, the longest oligomeric product of transpeptidation observed to date. Productive binding of the dipeptide substrates into the active site groove of pepsin required an induction period of several minutes. Quenching experiments suggested the presence of strongly bound intermediate forms of Leu and Leu-Leu prior to observation of any enzyme-free products. The finding of the tetrapeptide as a primary product is discussed as an instance where transpeptidation of the tripeptide competes successfully with the action of pepsin subsite S3 as a trigger for product release.
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PMID:Transpeptidation reactions of porcine pepsin. Formation of tetrapeptides from dipeptide substrates. 313 36

The pepsin extraction of group A type 1 streptococci for the isolation of M protein fragments was studied at different pH values and at different time intervals. The extracts were compared by SDS PAGE and fused rocket immunoelectrophoresis. Type 1 M protein fragments were prepared in preparative scale by pepsin extraction of type 1 streptococci at pH 5.5 for 60 min. The fragments were separated by affinity chromatography on immobilized fibrinogen and finally purified for sequence studies by gel chromatography. Pepsin extraction of group A type 3 streptococci was also studied at different pH values. In contrast to type 1, the SDS PAGE pattern changed drastically in dependence on the pH. Affinity chromatography on immobilized fibrinogen is also effective in the separation of the pH 5.5 type 3 streptococcal pepsin extract.
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PMID:Type 1 and 3 M-proteins of Streptococcus pyogenes: peptic extraction and fibrinogen binding properties. 313 67


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