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)

The conversion of plasminogen proactivator to plasminogen activator by Hageman factor fragments results in the generation of chemotactic activity for human neutrophils. This chemotactic activity can be distinguished from that generated by Hageman factor activation of prekallikrein and is demonstrable in plasma that is genetically deficient in prekallikrein (Fletcher factor deficiency). Both the plasminogen-activating activity and chemotactic activity produced by the interaction of Hageman factor fragments and plasminogen proactivator to yield plasminogen activator were inhibited by diisopropyl fluorophosphate (DFP) indicating an essential role for the enzymatic site in both these activities. The finding that the plasminogen proactivator tolerated a dose of DFP, which completely inactivated the plasminogen activator, reveals that the active site is protected in the precursor protein.
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PMID:The fibrinolytic pathway of human plasma. II. The generation of chemotactic activity by activation of plasminogen proactivator. 472 52

The human endogenous retrovirus type K (HERV-K) family codes for the human teratocarcinoma-derived retrovirus (HTDV) particles. The existence of the envelope protein (ENV) of HERV-K encoded by the subgenomic env mRNA has not yet been demonstrated. To study the genetic requirements for successful expression of ENV, we have constructed a series of recombinant HERV-K env expression vectors for infection and transfection experiments in insect cells and mammalian cells, respectively. Six baculovirus constructs bearing full-length or truncated HERV-K env with or without homologous or heterologous signal peptides were used for infections of insect cells. All recombinant baculoviruses yielded ENV proteins with the expected molecular masses. The full-length 80- to 90-kDa HERV-K ENV protein including the cORF leader sequence was glycosylated in insect cells. In addition, the 14-kDa cORF protein was expressed due to splicing of the full-length env mRNA. The ENV precursor protein is not cleaved to the surface (SU) and transmembrane (TM) glycoproteins; it does not appear on the surface of infected insect cells and is not secreted into the medium. For ENV expression in COS cells, plasmid vectors harboring the cytomegalovirus immediate-early promoter/intron A element and the tissue plasminogen activator (t-PA) signal peptide or the homologous HERV-K signal peptide upstream of the env gene were employed. Glycosylated and uncleaved ENV was expressed as in GH teratocarcinoma cells but at higher levels. The heterologous t-PA signal sequence was instrumental for expression of HERV-K ENV on the cell surface. Hence, we have shown for the first time that the HERV-K env gene has the potential to be expressed as a full-length envelope protein with appropriate glycosylation. In addition, our data provide explanations for the lack of infectivity of HERV-K/HTDV particles.
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PMID:Expression of human endogenous retrovirus type K envelope glycoprotein in insect and mammalian cells. 906 Jun 28

A fibrinogen-clotting enzyme designed as jerdonobin-II was isolated from the venom of Trimeresurus jerdonii. It differed in molecular weight and N-terminal sequence with the previously isolated jerdonobin, a thrombin-like enzyme from the same venom. The enzyme consists of a single polypeptide chain with molecular weights of 30,000 and 32,000 under non-reducing and reducing conditions, respectively. Jerdonobin-II showed weak fibrinogen clotting activity and its activity unit on fibrinogen was calculated to be less than one unit using human thrombin as standard. The precursor protein sequence of jerodonobin-II was deduced from cloned cDNA sequence. The sequence shows high similarity (identity=89%) to TSV-PA, a specific plasminogen activator from venom of T. stejnegeri. Despite of the sequence similarity, jerdonobin-II was found devoid of plasminogen activating effect. Sequence alignment analysis suggested that the replacement of Lys239 in TSV-PA to Gln239 in jerdonobin-II might play an important role on their plasminogen activating activity difference.
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PMID:Molecular characterization of a weak fibrinogen-clotting enzyme from Trimeresurus jerdonii venom. 1568 74

Based on the strong penetration capacity of near infrared lights (NIRs) and different absorption of oxyhemoglobin and deoxyhemoglobin in NIRs region, a novel noninvasive method, with the aid of an airproof-equilibrium apparatus, was developed to determine the oxygen binding-releasing capacity, including oxygen dissociation curve (ODC) and P(50), of the hemoglobin-loaded polymeric nanoparticles (HbP) in this study. The measured ODC of the PLA-PEG HbP was very close to that of the native hemoglobin, and the corresponding P(50) (26.1 mmHg) was also near to the native precursor protein (27.3 mmHg), indicative of the validity of the method proposed. To further verify the method proposed, the oxygen binding-releasing capacity of the HbPs prepared by PCL, PCL-PEG, PLA were also investigated with human blood as control. These results indicated that the method developed here enabled accurate and noninvasive determination of the oxygen binding-releasing capacity of the biodegradable polymeric oxygen carriers.
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PMID:A noninvasive method for measuring the oxygen binding-releasing capacity of hemoglobin-loaded polymeric nanoparticles as oxygen carrier. 1919 10