Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00750 (PLA)
 16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have observed that treatment of rabbit synovial fibroblasts with proteolytic enzymes can induce secretion of collagenase (EC 3.4.24.7) and plasminogen activator (EC 3.4.21.-). Cells treated for 2-24 hr with plasmin, trypsin, chymotrypsin, pancreatic elastase, papain, bromelain, thermolysin, or alpha-protease but not with thrombin or neuraminidase secreted detectable amounts of collagenase within 16-48 hr. Treatment of fibroblasts with trypsin also induced secretion of plasminogen activator. Proteases initiated secretion of collagenase (up to 20 units per 10(6) cells per 24 hr) only when treatment produced decreased cell adhesion. Collagenase production did not depend on continued presence of proteolytic activity or on subsequent cell adhesion, spreading, or proliferation. Routine subculturing with crude trypsin also induced collagenase secretion by cells. Secretion of collagenase was prevented and normal spreading was obtained if the trypsinized cells were placed into medium containing fetal calf serum. Soybean trypsin inhibitor, alpha(1)-antitrypsin, bovine serum albumin, collagen, and fibronectin did not inhibit collagenase production. Although proteases that induced collagenase secretion also removed surface glycoprotein, the kinetics of induction of cell protease secretion were different from those for removal of fibronectin. Physiological inducers of secretion of collagenase and plasminogen activator by cells have not been identified. These results suggest that extracellular proteases in conjunction with plasma proteins may govern protease secretion by cells.
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PMID:Proteases induce secretion of collagenase and plasminogen activator by fibroblasts. 20 72

When messenger RNA (mRNA) from both untreated and phorbol ester-treated melanoma cells is translated in simple reticulocyte lysates, tissue-type plasminogen activator can be immunoprecipitated by an affinity-purified antibody as a approximately 52,000 mol wt protein, with no detectable biological (plasminogen activating) activity. When the reticulocyte lysate system is supplemented with a preparation of microsomal membranes, biological activity becomes detectable and a 63,000 mol wt protein can be immunoprecipitated with the same antibody. Furthermore, when natural tissue-type plasminogen activator (mol wt approximately equal to 70,000) is incubated with different glycosidases, distinct alterations in the electrophoretic mobility of the molecules are observed, together with alterations in the level of biological activity. While treatment with neuraminidase and beta-galactosidase caused decreases in activity, alpha-mannosidase caused an increase. These results suggest that the carbohydrate part of the molecule can influence its biological behavior.
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PMID:Influence of carbohydrate side chains on activity of tissue-type plasminogen activator. 308 8

This study concerned the resolution of rat pituitary FSH utilizing chromatofocusing. Among the 11 components resolved and positively identified, ten had apparent isoelectric points (pI) between 3.1 and 5.1. Approximately 1% of pituitary FSH eluted at pH 9.4. Treatment with varying amounts of neuraminidase followed by refocusing generated FSH components of higher pI values. Treatment with other glycosidases did not alter the elution characteristics in chromatofocusing, while exclusion chromatography established an inverse relationship between apparent molecular weight and pI. Dose-response curves of various FSH components and of the reference preparation in the current radioimmunoassay system were parallel to each other. A study of their in-vitro bioactivity, utilizing granulosa cells which produce a plasminogen activator due to FSH in a dose-dependent manner, provided the following evidence: increased acidity of the components led to an increase of maximum response and an increase of the dose necessary for half-maximum response. Considering the observed alterations in the heterogeneity of FSH with changing physiological states of the animal, it is concluded that qualitative changes of the FSH molecule are perhaps involved in a modulatory role in the biopotencies of the hormone.
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PMID:Heterogeneity of rat FSH by chromatofocusing: studies on in-vitro bioactivity of pituitary FSH forms and effect of neuraminidase treatment. 392 42

The present studies examined the biochemical characteristics which were carried on from parent cells during fusion of human skin fibroblasts (HSF) with spleen cells of BALB/c mice preimmunized with hormone-responsive and nonresponsive human malignant melanoma cells (HMMC-ShA and HMMC-SR). The melanoma cells used as immunogens were either unmodified or preincubated with vibrio cholera neuraminidase (VCN), with estradiol (E), or with progesterone (P). Responsiveness was monitored by (3H) thymidine and (35S) methionine incorporation. Responsiveness to estradiol, concanavalin A (Con A) and to phytoheamagglutinin (PHA) were carried out, whereas malignancy was suppressed extensively in the cloned hybrids. On the immunizing tumor cells, VCN treatment enhanced (3H) thymidine but reduced (35S)-methionine incorporation and malignancy of the estradiol responsive melanoma cells (HMMC-ShA). VCN treatment enhanced (3H)-thymidine incorporation, but had no effect on (35S)-methionine incorporation and malignancy of the estradiol nonresponsive HMMC-SR cells. Estradiol treatment enhanced plasminogen activator (PA) activity and malignancy, whereas progesterone treatment reduced (inhibited) plasminogen activator activity and suppressed malignancy of the immunizing tumor cells. The PA from estradiol-responsive and from nonresponsive melanoma cells differed in their electrophoretic mobility on polyacrylamide gel electrophoresis.
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PMID:Correlation between plasminogen activator activity of immunizing tumor cells and complement-mediated cytotoxic antibodies secreted by cloned hybrid cells. 719 36

A rapid (< 10 min) one-step capillary isoelectric focusing (cIEF) method was developed to monitor charged glycoforms of recombinant human tissue-type plasminogen activator (rt-PA). Focusing takes place between the detector and the anode and the electro-osmotic flow (EOF) sweeps the separated glycoforms past the detector, towards the cathode. The separation uses a neutral coated capillary and hydroxypropylmethylcellulose (HPMC) to reduce the EOF to a constant and reproducible value. The method uses an ampholyte mix with a 50:50 ratio of pH 5-8 and pH 3-10 ampholytes in 4 M urea and 0.1% HPMC to produce maximal resolution whilst maintaining protein solubility during focusing. The electropherograms were compared to isoelectric focusing (IEF) slab gels of samples of intact rt-PA. In both cases approximately ten charged species could be detected. Data analysis indicated that the intra-assay precision was < 5% for peak migration times and < 10% for normalized peak areas. The number of charged species detected by each of the two methods was consistent for samples of intact rt-PA, rt-PA types I and II and for neuraminidase-digested rt-PA. Overall the data indicate that the automated cIEF method can be an adjunct to slab-gel IEF in the characterization and routine analysis of recombinant glycoproteins.
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PMID:Rapid one-step capillary isoelectric focusing method to monitor charged glycoforms of recombinant human tissue-type plasminogen activator. 852 Jun 85

The application of high-performance liquid chromatography (HPLC), electrospray ionization mass spectrometry (ESI-MS) and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and selective enzymatic deglycosylation treatments is demonstrated in the analysis of glycosylation patterns in recombinant Desmodus salivary plasminogen activator, a heterogeneous glycoprotein. The sample was initially digested with a proteolytic enzyme (endoproteinase Lys-C) and then further treated with either PNGase F to remove N-linked carbohydrates or a combination of neuraminidase and O-glycosidase to remove sialic acid and O-linked carbohydrates. By comparison of the LC-ESI-MS peptide maps for the fully glycosylated and deglycosylated samples, it was possible to unambiguously identify the sites of N-linked glycosylation as well a number of N-linked glycopeptides. The O-link glycopeptides, which are present at low level ( < 1%), were not detected prior to the deglycosylation, nor could changes in peptide elution in the map following deglycosylation be correlated with potential O-linked glycosylation sites.
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PMID:Application of high-performance liquid chromatograph-electrospray ionization mass spectrometry and matrix-assisted laser-desorption ionization time-of-flight mass spectrometry in combination with selective enzymatic modifications in the characterization of glycosylation patterns in single-chain plasminogen activator. 864 33