Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Supernatant fluids from murine spleen cell cultures incubated with concanavalin A for 48 hr contain a factor(s), soluble immune response suppressor (SIRS), which suppresses plaque-forming cell responses to sheep erythrocytes by murine spleen cells in vitro. In the present studies, some of the biochemical and biophysical properties of SIRS were investigated. SIRS was non-dialysable; the suppressive activity was stable at 56 degrees C for 30 min, but was destroyed by treatment at 70 degrees C for 30 min, 80 degrees C for 10 min, or at pH 2. The suppressive activity was not absorbed by the stimulating antigen, SRBC, or antisera against murine IgG or mu-chain, suggesting that SIRS does not contain immunoglobulin determinants. Murine spleen and thymus, but not kidney cells, however, absorbed SIRS activity. Enzyme treatments revealed that SIRS was resistant to DNase and RNase, but was destroyed by trypsin and chymotrypsin. In gel filtration with Sephadex G-100, SIRS activity eluted in the fraction corresponding to m.w. in the range between 48,000 and 67,000. With polyacrylamide gel electrophoresis, SIRS activity migrated in the region cathodal to albumin. Isopycnic centrifugation in a cesium chloride gradient suggested that SIRS is a glycoprotein. These supernatant fluids with SIRS activity were also found to contain macrophage migration inhibitory factor (MIF). In the experiments using gel filtration, polyacrylamide gel electrophoresis, and isopycnic centrifugation to fractionate supernatant fluids, SIRS and MIF activity were found in the same fractions, and to date we have been unable to dissociate definitively SIRS activity from MIF activity.
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PMID:Biological expressions of lymphocyte activation. V. Characterization of a soluble immune response suppressor (SIRS) produced by concanavalin A-activated spleen cells. 0 95

Extracts of the marine polychaetous annelid, Amphitrite ornata, agglutinate rat, rabbit, chicken and human erythrocytes and in other work have been shown to inhibit the growth of Ehrlich ascites tumors in mice. Fractionation of extracts on Sephadex G-100 gave three active fractions with molecular weights of 30 000, 54 000 and 100 000. The 30 000 dalton fraction (B) was purified 72-fold by ammonium sulfate precipitation, gel filtration and preparative disc gel electrophoresis. The purified hemagglutinin, amphitritin, was homogenous on analytical disc gel electrophoresis at four different pH values and gave a sharp boundary in sedimentation velocity ultracentrifugation. The three fractions showed paralled specificity toward rat and chicken erythrocytes, the former giving the higher titer. The purified agglutinin was active toward human blood groups A, B and O and exhibited 4-fold higher activity toward group A. The hemagglutinin titer against rat red blood cells was lowered only by N-acetylgalactosamine, the terminal sugar residue of the group A determinant. None of the saccharides tested inhibited agglutination of chicken erythrocytes. Hemagglutinin activity was insensitive to dialysis or treatment with EDTA. The activity was not affected by digestion with trypsin or pronase, but was destroyed by phenol extraction. Analytical disc gel electrophoresis showed one protein band with high anodal mobility at pH 8.5, which was not affected by proteolytic enzymes but was removed by phenol. Activity was unaffected by heating at 70 degrees C for 30 min but was destroyed by similar treatemtn at 85 degrees C. Activity was at a maximum at pH 7-9 and decreased reversibly down to pH 4 at which point it was irreversibly inactivated. The higher molecular weight agglutinin (A1) could be dissociated to give amphitritin by treatment with 6M urea of precipitation in 55% (NH4)2SO4. This dissociation was not reversed by dialysis. Amphitritin is a glycoprotein with a molecular weight determined by gel filtration of 30 000 and by approach to equilibrium sedimentation of 32 000. Amino acid analysis showed a preponderance of aspartic and glutamic acids and relatively large amounts of glycine, proline, alanine, valine and cysteine. The carbohydrate moeity which represented 12.8% of the molecule, contained mannose, galactose, glucosamine and sialic acid. Amphitritin is the first hemagglutinin to be isolated from a polychaetous annelid.
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PMID:Isolation and characterization of a hemagglutinin from Amphitrite ornata, a polychaetous annelid. 0 17

We have investigated the interaction between concanavalin A-agarose (Con A-agarose) and thyroid peroxidase, an integral membrane protein found in the 105,000 X g, 1-h particulate fraction of thyroid tissue. An intact form of porcine thyroid peroxidase was obtained by solubilization with the nonionic detergent Triton X-100 and two fragmented, hydrophilic forms of the enzyme were prepared by trypsin treatment of the membrane. The three types of thyroid peroxidase bind to Con A-agarose and can be eluted with alpha-methyl-D-mannoside. The alpha-methyl-D-mannoside eluate of the most purified thyroid peroxidase preparation has been analyzed by polyacrylamide gel electrophoresis. Peroxidase activity corresponds with a glycoprotein band. The binding of thyroid peroxidase to Con A-agarose can be inhibited by sugars in the following order: alpha-methyl-D-mannoside greater than D-mannose greater than alpha-methyl-D-glucoside greater than D-glucose greater than D-galactose. This order of specificity is typical of Con A-sugar interactions. Furthermore, inactivation of the carbohydrate binding site of Con A by demetallization greatly reduces the extent of thyroid peroxidase binding. Reactivation of the carbohydrate binding site by the addition of Ca2+ and Mn2+ to demetallized Con A-agarose restores thyroid peroxidase binding. These and other experiments suggest that htyroid peroxidase is, like several other peroxidases, a glycoprotein. In addition, the interaction between thyroid peroxidase and Con A-agarose may provide a new purification tool for thyroid peroxidase.
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PMID:Interaction of thyroid peroxidase with concanavalin A covalently coupled to agarose. 1 48

Sera from chickens naturally infected with Marek's disease herpesvirus (MDHV) form preciptin lines with at least two immunologically distinct soluble antigens designated MDHV-A and MDHV-B. Partial purification and characterization of the glycoprotein MDHV-A antigen was previously reported. MDHV-B was found predominantly in the sonically treated extracts of infected cells, in contrast to the predominantly extracellular MDHV-A. Analysis of these extracts from [14C]glucosamine-labeled cells by immunodiffusion with chicken anti MDHV-B serum negative for MDHV-A followed by autoradiography confirmed that MDHV-B was a common antigen between MDHV and herpesvirus of turkeys and revealed that it was also a glycoprotein. Because of their glycoprotein nature, both MDHV-A and MDHV-B bound to concanavalin A affinity chromatography columns and could then be eluted by alpha-methyl-D-mannoside and recovered for further analysis. Concanavalin A affinity chromatography was an excellent technique for initial purification of MDHV-A and MDHV-B, since approximately 5- and 15- fold purification, respectively, was achieved in a single simple step. MDHV-B was resistant to trypsin under conditions where MDHV-A was sensitive, but was similar to MDHV-A in resistance to pH 2.0 and to 1.0 or 2.0 M urea and 0.05% Brij 35. Partially purified MDHV-B was analyzed by sucrose gradient sedimentation, isoelectric focusing, and gel filtration on Sephadex G-200 in the presence of 1.0 or 2.0 M urea and 0.05% Brij 35 to purify the antigen and to determine its physical and chemical properties in comparison with those already reported for MDHV-A. MDHV-B had a much lower isoelectric point in pH 4,54, a higher sedimentation coefficient of 4.4S, and a greater molecular weight of 58,250. These data indicate that MDHV-B is physically distinct from MDHV-A antigen, although the size difference is not sufficient to allow for effective separation. In contrast, the isoelectric point difference of greater than 2 pH units makes isoelectric focusing an effective means of purifying the antigens free of one another. The four-step purification procedure achieved greater than 200-fold purification of MDHV-B. Immunization of rabbits with this highly purified antigen results in the preparation of antisera that appeared monospecific for MDHV-B in immunodiffusion.
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PMID:Marke's disease herpesviruses. III. Purification and characterization of Marek's disease herpesvirus B antigen. 2 34

The effects of intravenously administered rat alpha1 macroglobulin (alpha1M), alone and in combination with pancreatic trypsin, on the synthesis of alpha1 acute-phase globulin (alpha1AP globulin) have been measured in the isolated perfused rat liver 24 h after injection. Maximum promotion (approximately five-fold) of alph1AP globulin synthesis was observed after administration of alpha1M complexed with trypsin or alpha1M alone, which after purification had lost most of its trypsin-protein-esterase (T.P.E.) activity. Slightly lesser but still significant degrees of enhancement (approximately four-fold) of alpha1AP globulin synthesis resulted from the injection of alpha1M alone or complexed with trypsin, which after purification had retained sitnificant T.P.E. activity. All these responses were greater than those generated by injection of trypsin or plasma alone, or rabbit plasma complexed with trypsin. However, the synthetic response did not reach the maximum rate observed 24 h after an intramuscular injection or sterile turpentine. An hypothesis is proposed for the role of alpha1 macroglobulin (and its homologue in man, alpha2 macroglobulin) in the mediation of the acute-phase synthetic response by the liver. This predominantly intravascular glycoprotein serves as the principal circulatory porteinase binder. Proteinases released in response to tissue injury, necrosis or inflammation would be bound and inactivated by alpha1M, and in turn the alpha1M-proteinase complex would stimulate the liver to synthesize a number of acute-phase proteins. Certain of these, e.g. alpha2 acute-phase globulin also possess proteinase binding activity and, being of low molecular weight, would be more effective than alpha1M in the inactivation of released tissue enzymes at extravascualr sites. The data presented in this paper are compatible with this biphasic role for plasma proteinase inhibitors in the biological response to injury.
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PMID:A proposed role for alpha1 macroglobulin in the promotion of alpha1 acute-phase globulin synthesis by the perfused rat liver. 5 47

An inhibitor of neutral subtilopeptidase [EC 3.4.24.4] was purified from porcine serum by salting out with (NH4)2SO4, chromatography on anion exchange sephadex, gel filtration with Sepharose 6B, and isoelectric focusing. The preparation was homogeneous by electrophoretic and ultracentrifugal criteria, and was shown to be a glycoprotein with a molecular weight of 740,000. It inhibited the caseinolytic activities of thermolysin, subtilisin, trypsin [EC 3.4.21.4], and alpha-chymotrypsin [EC 3.4.21.1] as well as that of neutral subtilopeptidase by an equimolar binding to those proteolytic enzymes. SDS-polyacrylamide gel electrophoresis after reduction with beta-mercaptoethanol indicated that the inhibitor was made up of four subunit monomers having a molecular weight of 190,000. From comparisons of its physiocochemical and inhibitory properties with those of well-investigated plasma proteins, the inhibitor was identified as alpha2-macroglobulin. On treatment of the inhibitor with neutral subtilopeptidase, a protein with a molecular weight of 95,000 appeared after treatment with SDS and beta-mercaptoethanol, suggesting that a peptide bond susceptible to the enzyme exists near the mid-point of the subunit chains.
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PMID:A neutral subtilopeptidase inhibitor from porcine serum some evidence for alpha2-macroglobulin. 5 60

Sialic acid has been shown to be part of the antigenic determinant of the Thy-1.2 alloantigen as expressed by the murine cell line S-49.1 TB-2-3 (S-49). This conclusion is based on the loss of cytotoxic inhibitory activity by the action of neuraminidase on the Thy-1.2 alloantigen. Also, sialic acid has the ability to inhibit the cytotoxic assay of AKR anti-C3H Thy-1.2 serum for S-49 cells. Further evidence for the protein nature of the Thy-1.2 alloantigen is apparent by trypsin digestion. Possibly the Thy-1.2 alloantigen as expressed on S-49 cells is a glycoprotein.
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PMID:Studies on the antigenic determinants of the Thy-1.2 alloantigen as expressed by the murine lymphoblastoid line S-49.1 TB-2-3. 5 44

A polar, nonpenetrating compound of high specific activity, diazotized (125I)-diiodosulfanilic acid (DD125ISA), has been developed as a label for exposed proteins of the human platelet plasma membrane, and platelet proteins and the pattern of labeling have been studied with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). That DD125ISA binds specifically to membrane proteins was demonstrated by: (1) the specific activity of isolated membrane protein was five to seven times that of whole platelet protein and (2) no proteins of intact platelets were labeled which were not represented in the isolated plasma membrane. That the DD125ISA-labeled membrane proteins were exposed on the cell surface was demonstrated by: (1) DD125ISA-labeled proteins were altered by trypsin treatment of intact, labeled platelets and (2) the pattern of labeling produced by reaction of isolated membranes with DD125ISA was quite different from that produced by the labeling of intact platelets. Analysis of platelet membrane proteins by SDS-PAGE demonstrated the glycoproteins previously described at 150,000 daltons (termed glycoprotein I) and 92,000 daltons (glycoprotein III) but we could discriminate two apparently distinct glycoproteins in the intermediate region (IIa: 125,000 daltons, and II: 118,000 daltons). Glycoproteins I and III were constant whereas IIa was clearly visible only in unreduced samples and II was predominant in reduced samples. Reaction of DD125ISA with intact platelets resulted in equal labeling of three of these four membrane glycoproteins (IIa, II, and III). The pattern of exposed proteins on the platelet surface labeled by DD125ISA was different from lactoperoxidase-131I, which labeled predominantly the 92,000 dalton glycoprotein, as demonstrated by simultaneous SDS-PAGE analysis. Therefore three glycoproteins of the human platelet plasma membrane are exposed to a radioisotope probe on the platelet surface and are accessible for contact interactions.
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PMID:Studies on platelet plasma membranes. I. Characterization of surface proteins of human platelets labeled with diazotized (125i)-diiodosulfanilic acid. 6 Apr 57

Plasma glycoprotein synthesis in normal and vitamin A-deficient rats was investigated by injecting the rats with labeled carbohydrate precursors and then fractionating their plasmas on DEAE-Sephadex. Plasma from deficient rats showed a consistent depression of 30% in the uptake of label into a peak eluting with 0.23 M NaCl. The major component of this peak was identified as the rat alpha1-macroglobulin, based on its molecular weight (800,000), its mobility on cellulose acetate electrophoresis and its ability to bind trypsin. Although the alpha1-macroglobulin synthesis appeared to be depressed by 30%, its fractional turnover rate was not affected by vitamin A deficiency (t 1/2 = 18 hours). The trypsin-binding ability of this glycoprotein was used as a comparative measure of its concentration, and the results confirmed that serum levels of this glycoprotein were lower in deficient rats. In severe deficiency, alpha1-macroglobulin levels dropped to between 10% and 20% of normal levels.
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PMID:A plasma glycoprotein depressed in vitamin A deficiency in the rat: alpha 1-macroglobulin. 6 42

Ovarian carcinoma contains an antigen (TA) which is stable at 100 degrees. Rabbit antisera to glycoprotein-rich extracts of tumors detect TA in 70 per cent of ovarian malignancies, in some benign ovarian cysts, certain normal lung preparations, normal cervix, and squamous-cell carcinoma of the cervix. Highest levels may be associated with mucin secretion. No detectible antigen was present in normal ovary, plasma, A, B, and O erythrocytes, leukocytes, placenta, brain, heart, liver, corpus uteri, spleen, skeletal muscle, or kidney. Prolonged digestion of boiled tumor extracts with papain, trypsin, chymotrypsin, on Sephadex G-150 corresponding to a globular protein of 27,000 to 36,000 molecular weight. A beta-globulin mobility is seen in immunoelectrophoresis. It appears that TA differs in tissue specificity and molecular size from other known ovarian cancer associated antigens.
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PMID:A thermostable antigen associated with ovarian cancer. 6 15


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