Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0272170 (SDS)
 50,377 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Several species of cysteine proteinase inhibitors have been demonstrated in the greyhound intervertebral disc which were resolved into four species (Mr 15,800, 16,600, 17,200 and 17,800) by gelatin-SDS-polyacrylamide gel electrophoresis. Reductive alkylation did not affect their inhibitory capability nor their electrophoretic migration on gelatin-SDS-polyacrylamide gel electrophoresis. The cysteine proteinase inhibitors from the nucleus pulposus and annulus fibrosus were identical as assessed by the aforementioned criteria, although the level in the nucleus was found to be higher than that in the annulus. Ion-exchange chromatography demonstrated distinct acidic and basic forms of the disc cysteine proteinase inhibitor. The latter species was the most abundant and its Mr was determined to be 16,900 by gelatin-SDS-polyacrylamide gel electrophoresis. Both forms were shown to be strongly inhibitory against the cysteine proteinases, papain and ficin, but were less strongly inhibitory against cathepsin B (EC 3.4.22.1). Presumably these disc cysteine proteinase inhibitors play a regulatory role in the metabolism of proteoglycans and collagen by endogenous cysteine proteinases.
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PMID:Cysteine proteinase inhibitors of the canine intervertebral disc. 325 94

Protease digestion of the ADP-ribosylated pertussis toxin substrate (PTS) protein was carried out after solubilization with SDS (Cleveland gels) and in the intact membrane. Cleveland gel analysis showed substantial similarities in the maps for the PTS component in neutrophils, platelets and erythrocytes and also in the S49 AC-lymphoma cell line. In the intact membrane ADP-ribosylation followed by digestion showed limited access of proteases to the PTS component. Of eight proteases tested, only papain and Staphylococcus aureus gave substantial digestion. This pattern was observed in the human platelet, erythrocyte and neutrophil plasma membranes. When the sequence was reversed and ADP-ribosylation was carried out after protease digestion, a very different pattern was observed with much greater susceptibility to digestion being noted with several proteases. By contrast, analysis of the murine AC-membrane showed some minor variations in the digest patterns. In addition, under all three conditions tested, maps of the cholera toxin substrate for the human platelet showed remarkable similarities to those obtained with the pertussis toxin substrate. Our results indicate that the protease sensitive sites of the alpha subunit of PTS and protection from proteolysis after ADP-ribosylation are properties which are shared by the PTS components of human platelets, erythrocytes and neutrophils.
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PMID:Peptide mapping studies of the pertussis toxin substrate in human neutrophils, platelets and erythrocytes. 328 41

Protease and antiprotease activities were estimated in nasal secretions from patients with chronic sinusitis and nasal allergy, using [3H]-casein as substrate. In the purulent nasal secretions, strong protease activity was measured, but there was less activity in the allergic nasal secretions. In contrast, trypsin inhibitory activity in allergic nasal secretions was much higher than in nasal secretions from the patients with chronic sinusitis. A protease inhibitor was partially isolated from nasal secretions of the nasal allergic patients by Sephadex G-150 gel chromatography and characterized. This protease inhibitor has an apparent molecular weight of 10,000 D, determined by SDS-polyacrylamidegel electrophoresis. It depresses the activities of bovine pancreatic trypsin, bovine pancreatic chymotrypsin and proteases in nasal purulent secretions, whereas it does not inhibit porcine pancreatic elastase, papain, or human plasmin.
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PMID:A protease inhibitor from human allergic nasal secretions. 332 29

Recently, a protein isolated from the membrane of human E, the so-called C8 binding protein (C8bp), has been described. C8bp is characterized as a 65-kDa protein that binds to C8 and inhibits the C5b-9-mediated lysis in a homologous system. In the present study, membranes of peripheral blood cells were tested for the presence of C8bp by SDS-PAGE and immunoblotting. In all cells a protein band reacting with anti-C8bp was seen, the Mr, however, was only about 50 kDa. To further analyze the 50-kDa protein, we isolated the protein by phenol-water extraction and isoelectric focusing from papain-treated platelets. The isolated protein behaved similar to the E-derived C8bp: it inhibited the lysis of model target cells by C5b-9. To examine the function of C8bp in platelets, we tested platelets from patients suffering from paroxysmal nocturnal hemoglobinuria (PNH). These platelets were deficient in C8bp, being in accordance with their higher lytic susceptibility in vitro. In response to sublytic C5b-9 doses, the PNH platelets released considerably more serotonin and thromboxane B2 than normal platelets. By addition of purified C8bp, the thromboxane B2 release was suppressed, indicating that C8bp not only restricts the lytic complement attack, but also regulates the C5b-9-mediated stimulation of target cells. Thus, lack of C8bp might not only result in enhanced hemolysis, but also in enhanced stimulation of platelets, which in turn might contribute to the thrombotic complications seen in some PNH-type III patients.
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PMID:Paroxysmal nocturnal hemoglobinuria. Enhanced stimulation of platelets by the terminal complement components is related to the lack of C8bp in the membrane. 336 Nov 26

Besides the Coomassie-blue-stained band corresponding to mature bacterioopsin two additional bands of slightly higher apparent molecular masses were observed in purple membrane preparations from Halobacterium halobium by SDS-PAGE. The staining intensity within the triple band pattern varied with the age of the cell culture. For cells in the stationary growth phase the lower band, corresponding to mature bacterioopsin, is the predominant one. Immunodetection and site-specific proteolysis with papain identified the upper band as originating from the previously described precursor of bacterioopsin with its 13-amino-acid-long N-terminal presequence. Our results suggest that the intermediate band is due to a modified precursor of bacterioopsin with a truncated presequence of about eight amino acids. A two-step mechanism for the processing of pre-bacterioopsin to the mature protein in this archaebacterium is proposed.
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PMID:Bacteriorhodopsin precursor is processed in two steps. 337 64

Xanthine oxidase (EC 1.2.3.2) was purified from fresh cows' milk by differential centrifugation and hydroxylapatite chromatography in the absence of reducing agents and proteases. The purified isolate possessed an absorbance at 280 nm:absorbance at 450 nm ratio of 4.84; an absorbance (1 cm at 280 nm 1%) of 11.9; an activity:absorbance at 450 nm of 141, a specific activity of 3.59 units/mg; and detectable dehydrogenase activity. The enzyme preparation was obtained in a reversible oxidase form that could be partially converted to xanthine dehydrogenase in the presence of 10mM dithiothreitol or 1% mercaptoethanol. Amino acid analyses revealed that the enzyme was hydrophobic in nature and that lysine constituted its N-terminal residue. The protein contained 22 disulfide and 38 sulfhydryl groups, four of which were detectable in the undenatured protein complex. Discontinuous PAGE in the presence of selected dissociation agents did not result in further resolution. Sodium dodecyl sulfate-PAGE of the purified enzyme revealed a sharp zone with a molecular weight of 151,000 +/- 4000 (i.e., monomer). The purified enzyme exhibited oxidase activity in the presence of 6 M urea and following limited proteolysis by trypsin, chymotrypsin, plasmin, pancreatin, pepsin, and papain. Proteolyzed xanthine oxidase migrated as a single zone in polyacrylamide gels in the presence and absence of dissociating agents such as 1% mercaptoethanol and 6 M urea. Restricted digestion of xanthine oxidase by proteases was indicated by the presence of three major zones with molecular weights ranging from 85,000 to 100,000, 30,000 to 35,000, and 18,000 to 20,000 commonly observed in SDS gels. Amino acid profiles of the principal peptidyl fragments of trypsin-cleaved xanthine oxidase indicated their hydrophobic nature and lysine as the N-terminal residue for all fragments.
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PMID:Characteristics of purified cows' milk xanthine oxidase and its submolecular characteristics. 339 6

A low-Mr Clara-cell secretory protein, CCSP, previously shown to be a major secretory product of Clara cells, was isolated from rabbit lung lavage effluents. CCSP accounted for 4.4 +/- 0.5% of the protein in the soluble phase of cell- and surfactant-free pulmonary lavage effluents (LE). Purification of this protein from LE was achieved in two steps. First, the LE was acidified with HCIO4 and, secondly, CCSP was isolated by gel-exclusion chromatography on Sephadex G-50. Purified CCSP was homogeneous by SDS/polyacrylamide-gel electrophoresis (PAGE), consisting of a single major isoform with a pI of 6.0. The Mr of CCSP was 5800 according to SDS/PAGE under reducing conditions and 12,600 under non-reducing conditions. However, by gel chromatography the Mr of the protein under non-reducing conditions was 12,400 and under reducing conditions it increased to 15,000. The discrepancy obtained by using these two techniques was attributed to anomalous electrophoretic mobilities of the protein in its reduced state. The molecule contained three half-cystine residues, but no free thiol groups, and tryptophan was not detectable. The first seven N-terminal amino acid residues were Gly-Ile-Xaa-Pro-Arg-Phe-Ala-. The third residue was not identified. CCSP showed inhibitory activity against the thiol proteinase papain (50% inhibition at 4 microM-CCSP), but only weak activities against human polymorphonuclear-leucocyte elastase, and bovine trypsin. The molecule was not digested by, and did not complex with, trypsin. CCSP was immunochemically different from surfactant apoprotein B (Mr 10,000) present in rabbit lung surfactant. This study is the first partial characterization of the major secretory protein of rabbit lung Clara cells.
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PMID:Purification, characterization and proteinase-inhibitory activity of a Clara-cell secretory protein from the pulmonary extracellular lining of rabbits. 343 51

Venoms from eight snakes have been screened for inhibitory activity against papain, strong activity being found in that of the African puff adder, Bitis arietans. The inhibitor from B. arietans venom has been purified by affinity chromatography on carboxymethyl-papain-Sepharose and ion-exchange chromatography. The inhibitor had an apparent Mr of 13,000 in SDS/polyacrylamide gel electrophoresis, and pI value of 6.5 (major component) or 6.3 (minor component). Values of Ki for the inhibition of papain, cathepsin B and dipeptidyl peptidase I were 0.10, 2.7 and 0.23 nM, respectively; chicken calpain was not inhibited.
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PMID:A cystatin-like cysteine proteinase inhibitor from venom of the African puff adder (Bitis arietans). 350 Jul 13

125I-labelled heat-labile toxin (from Escherichia coli) and 125I-labelled cholera toxin bound to immobilized ganglioside GM1 and Balb/c 3T3 cell membranes with identical specificities, i.e. each toxin inhibited binding of the other. Binding of both toxins to Balb/c 3T3 cell membranes was saturable, with 50% of maximal binding occurring at 0.3 nM for cholera toxin and 1.1 nM for heat-labile toxin, and the number of sites for each toxin was similar. The results suggest that both toxins recognize the same receptor, namely ganglioside GM1. In contrast, binding of 125I-heat-labile toxin to rabbit intestinal brush borders at 0 degree C was not inhibited by cholera toxin, although heat-labile toxin inhibited 125I-cholera toxin binding. In addition, there were 3-10-fold more binding sites for heat-labile toxin than for cholera toxin. At 37 degrees C cholera toxin, but more particularly its B-subunit, did significantly inhibit 125I-heat-labile toxin binding. Binding of 125I-cholera toxin was saturable, with 50% maximal of binding occurring at 1-2 nM, and was quantitatively inhibited by 10(-8) M unlabelled toxin or B-subunit. By contrast, binding of 125I-heat-labile toxin was non-saturable (up to 5 nM), and 2 X 10(-7) M unlabelled B-subunit was required to quantitatively inhibit binding. Neuraminidase treatment of brush borders increased 125I-cholera toxin but not heat-labile toxin binding. Extensive digestion of membranes with Streptomyces griseus proteinase or papain did not decrease the binding of either toxin. The additional binding sites for heat-labile toxin are not gangliosides. Thin-layer chromatograms of gangliosides which were overlayed with 125I-labelled toxins showed that binding of both toxins was largely restricted to ganglioside GM1. However, 125I-heat-labile toxin was able to bind to brush-border galactoproteins resolved by SDS/polyacrylamide-gel electrophoresis and transferred to nitrocellulose.
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PMID:Characterization of the receptor for cholera toxin and Escherichia coli heat-labile toxin in rabbit intestinal brush borders. 354 10

Monoclonal antibody 3A4 to islet cell surface antigen has been previously established in our laboratory, using hybridization of spleen lymphocytes from non-obese diabetic (NOD) mice transferred into immunologically incompetent recipient mice. In the present study, monoclonal islet cell surface antibody 5C12 could be newly obtained in the 10:1 ratio of NOD mice spleen cells and mouse myeloma cells (SP2/0) without any modifications. Protein A radioligand assay and indirect immunofluorescence on living cells showed that 5C12 antibody reacted to normal rat islet cells and cultured rat insulinoma cells (RIN-r), but not to cultured lymphocytes (Bri-7, IM-9) and Chang-liver cells. Analysis of 125I-labeled antibody binding revealed that unlabeled 5C12 effectively inhibited subsequent 125I-5C12 binding to RIN-r cells, whereas unlabeled 3A4 did not. The scatchard plot from these data showed the curvilinearity, and about 150,000 binding sites to antibody per RIN-r cell were counted. The treatment of RIN-r cells with papain and neuraminidase reduced the binding of 5C12 to RIN-r cells, whereas the effect of trypsin was not observed. Immunoprecipitation of 125I-labeled insulinoma cell lysates followed by SDS-PAGE and autoradiography indicated that 5C12 recognized 105K dalton cell surface protein in RIN-r cells. Immunoblotting also showed that 5C12 antibody recognized 105K dalton cell surface protein in RIN-r cells. These results demonstrated that 5C12 was an important tool for clarifying the immunoresponse against certain antigenic determinants on pancreatic B cells. Furthermore, 5C12 has not only qualitatively and quantitatively improved diagnostic methodology, but it may also provide new reagents useful to the treatment and prevention of type 1 diabetes.
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PMID:[An analysis of islet cell surface antigen defined by monoclonal islet cell surface antibody 5C12]. 354 94


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