Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The distribution of glycosaminoglycans and glycoproteins has been studied in cytoplasmic and particulate fractions of neurons isolated in bulk from rat cerebrum. Lysis of the neurons in 25 mM sodium phosphate buffer at pH 7.5 released 20% of the protein and over 90% of the lactate dehydrogenase in a soluble form. Eighty-two percent of the chondroitin sulfate was also released, together with 55% of the heparan sulfate and 24-25% of the hyaluronic acid and glycoproteins. The chondroitin sulfate remaining in the membranes was completely depolymerized to disaccharides after treatment with chondroitinase ABC, and treatment of the neuronal membranes with 0.1% trypsin removed 55-63% of the chondroitin sulfate and heparan sulfate but only 25% of the sulfated glycoproteins. The results reported here support our previous conclusion that the soluble chondroitin sulfate proteoglycan of brain is largely a cytoplasmic constitutent of neurons (and astrocytes) and is not primarily present in nervous tissue as an extracellular ground substance.
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PMID:Presence of chondroitin sulfate in the neuronal cytoplasm. 28 11

Previously reported experiments suggested that an esterase or a protease, or both, might participate in the expression of human leukocyte migration inhibitory factor (LIF). To clarify this further, a wide variety of simple ester were tested for the ability to protect LIF against inactivation by the serine esterase inhibitor phenylmethylsulfonyl fluoride (PMSF). alpha-N-benzoyl-L-arginine ethylester (BAEE), a typical trypsin substrate, and bis-p-nitrophenyl phosphate (BNPP), a phosphodiester, were the only esters capable of retaining LIF activity in the presence of PMSF. Agents chemically closely related to these esters were inactive. Moreover, the protection afforded by BAEE and BNPP was the king that would be anticipated if the esters and irreversible inhibitor competed for the same site on LIF. Baee and BNPP also protected against inactivation by di-isopropylfluorophosphate (DFP), another irreversible serine esterase inhibitor. In addition, LIF-treated leukocytes partly escaped migration inhibition in the presence of BAEE and BNPP, respectively. These results indicate that human LIF contains a serine residue necessary for lymphokine activity. It is still not proved, however, that LIF as an enzyme is capable of hydrolyzing BAEE and BNPP, although it seems highly possible. The substrate specificities of a putative LIF enzyme are discussed on the basis of the chemical structure of BAEE and BNPP.
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PMID:Human leukocyte migration inhibitory factor (LIF). II. Partial biochemical characterization of the substrate specificities for this lymphokine. 32 60

Effects of treatments with proteolytic enzymes and protein-modifying reagents on flocculation of brewer's yeast IFO 2018 were investigated. The floc-forming ability of the yeast cells was irreversibly eliminated by treatment with papain, trypsin, chymotrypsin or pepsin, indicating that certain proteins on the cell surface participate in the yeast flocculation. Chemical modification with reagents, known to act on disulfide bridges, carboxyl and/or phosphate groups, phenolic groups, amino groups, and imidazole groups, also destroyed the ability to flocculate, although in some cases a high concentration (8 M) of urea was necessary in addition to protein-modifying reagents. Thus, it is suggested strongly that these functional groups of amino acid residues of the proteins are essential for the floc-forming ability of brewer's yeast cells.
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PMID:Effect of chemical modification of cell surface components of a brewer's yeast on the floc-forming ability. 33 19

Prostacyclin (PGI(2)) is an unstable prostaglandin which inhibits platelet aggregation and serotonin release and causes vasodilation. The PGI(2) activity produced by monolayers of cultured human endothelial cells and fibroblasts was measured by the ability of their supernates to inhibit platelet aggregation in platelet-rich plasma, or to inhibit thrombin-induced [(14)C]serotonin release from aspirin-treated, washed platelet suspensions. Monolayers of cultured human endothelial cells, stimulated with sodium arachidonate, thrombin, the ionophore A 23187, or trypsin, secreted PGI(2) into the supernatant medium. Monolayers of fibroblasts produced PGI(2) activity only when stimulated by arachidonate. "Resting," intact monolayers did not produce detectable PGI(2), nor did monolayers treated with ADP or epinephrine. Production of PGI(2) activity was abolished by treatment of the monolayers with indomethacin, tranylcypromine, or 15-hydroperoxy arachidonic acid. The PGI(2) activity of the supernates was destroyed by boiling or acidification. Inhibition of thrombin with diisopropylfluoro-phosphate, and of trypsin with soybean trypsin inhibitor, abolished the stimulation of PGI(2) production by these enzymes. Production of thrombin at a site of vascular injury could, by stimulating PGI(2) synthesis by endothelial cells adjacent to the injured area, limit the number of platelets involved in the primary hemostatic response and help to localize thrombus formation.
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PMID:Stimulation of endothelial cell prostacyclin production by thrombin, trypsin, and the ionophore A 23187. 36 56

After the seminiferous tubules were minced and washed with phosphate-buffered saline to remove sperms, spermatids and spermatocytes (Hoo and Bowles, 1971), they were repeatedly treated with 0.1% trypsin solution to liberate spermatogonia. It was concluded that the spermatogonial chromosomes can be analysed much more easily and accurately by this procedure than by previous ones.
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PMID:A new method for the preparation of mammalian spermatogonial chromosomes. 36 12

An improved purification procedure is described for the sigma subunit of escherichia coli DNA-dependent RNA polymerase [ribonucleoside triphosphate:RNA nucleotidyl-transferase, EC 2.7.7.6]. The method involves chromatography of purified RNA polymerase on single-stranded DNA-agarose, Bio-Rex 70, and finally Ultragel AcA44. The sigma factor obtained is electrophoretically pure with a yield of about 40%. A number of the chemical--physical properties of sigma are presented. A molecular weight of 82,000 was determined by phosphate buffered sodium dodecyl sulfate--polyacrylamide gel electrophoresis. Ultraviolet absorption spectra were used to determine an E280nm 1% of 8.4. The amino acid composition and 12-residue N-terminal sequence (Met-Glx-Glx-Asx-Pro-Glx-(Ser or Cys)-Glx-Leu-Lys-Leu-Leu) of sigma have been determined. The isoelectric focusing properties of sigma are presented. Denaturation--renaturation studies indicate that sigma is capable of an unusually rapid and complete recovery of activity after being subjected to denaturing conditions. A stable, 40,000-dalton fragment is generated from sigma by mild trypsin treatment.
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PMID:Purification and properties of the sigma subunit of Escherichia coli DNA-dependent RNA polymerase. 37 77

The electrophoretic mobilities of rough and smooth microsomes were studied using free electrophoresis in a sucrose gradient. Rough microsomes have a higher net negative surface charge but removal of the ribosomes decreases their mobility to that of smooth microsomes. Treatment with neuraminidase and phospholipases C and D does not affect the mobility of total smooth microsomes, but this mobility is increased by approximately 20% after trypsin and papain treatment and by approximately 12% after phospholipase A treatment. Further treatment of trypsin-digested smooth microsomes with phospholipase C re-establishes the original mobility. This effect is not caused by the removal of lipid phosphate groups, but by the liberation of negatively charged protein species that are normally buried under trypsin-sensitive proteins. Low concentrations of trypsin also solubilize enzyme proteins from smooth liver microsomes of phenobarbital-treated rats, but the electrophoretic mobility is not increased, indicating structural differences between induced and control membranes.
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PMID:Electrophoretic mobility of microsomes from rat liver. 40 61

An extracellular protein-polysaccharide-lipide (PPL) complex from exponentially growing cultures of Myxococcus virescens was purified by phosphate precipitation and gel chromatography. The high molecular weight slime polymer appeared homogenous upon isoelectric focusing. The PPL complex exhibited proteolytic activity against gelatin and the activity was only partly reduced by heat treatment. The function of the slime polymer as protein denatured was studied. The complex formed micelles similar to anionic detergents and it inhibited the precipitation and coagulation of proteins by trichloroacetic acid. Lysozyme was totally inactivated when treated with the PPL complex. By gel chromatography binding studies, the PPL complex was found to bind lysozyme in the ratio of 1 to 5.8 (w/w). After separation of added protein from the complex the anticoagulation effect on the protein remained. The biological function of the PPL complex was demonstrated with hemoglobin. When all susceptible peptide bonds in PPL-treated hemoglobin were hydrolyzed by trypsin only 20% in the urea-denatured protein were attacked. The combined role of slime and proteolytic activity is discussed.
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PMID:Myxobacterial slime and proteolytic activity. 41 87

A membrane-bound nucleotidase of Bacillus cereus T was solubilized by digestion with trypsin and subsequently purified more than 300-fold. The purified nucleotidase was most active on ribonucleoside 5'-monophosphates and was slightly less active (40 to 60%) on deoxyribonucleoside 5'-monophosphates and ribonucleoside 3'-monophosphates. In addition to hydrolytic activity, the nucleotidase preparation possessed phosphotransferase activity by which phosphate is transferred from a phosphate donor to the 5' position of nucleosides.
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PMID:Membrane-bound nucleotidase of Bacillus cereus. 41 44

Firmly united conjugant pairs of P. caudatum were easily separated by treatment with trypsin, 0.025--1.0 mg/ml in 2 mM phosphate buffer at pH 7.2. Cytological observations showed that pairs separated by this means undergo normal meiosis and subsequent prezygotic divisions. Microspectrophotometric comparisons of G1 micronuclei in the parent with those in clones derived from prematurely separated conjugants indicate usually the same DNA content in both. The stock dm -13, heterozygous for mating type gene loci, showed the definite ratio of segregation to 2 mating types in clones derived from prematurely separated conjugants. Those results suggest that the prematurely separated cells usually undergo autogamy.
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PMID:Induction of autogamy by treatment with trypsin in Paramecium caudatum. 42 71


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