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)

Allergen RC-13's amino acid composition was determined-Lys3, His1, Arg7, Asp6, Thr2, Ser11, Glu29, Pro2, Gly7, Ala4, Cys6, Val5, Met1, Ile3, Leu3, Tyr1; 91 residues. Partial specific volume and minimum molecular weight evaluated from this composition were, respectively, 0.694 cm3/g and 10,194. SDS-polyacrylamide gel electrophoresis performed in the reduced and alkylated form of the allergen revealed a single band, suggesting the existence of only one polypeptide chain in the molecule. Results obtained for carbohydrate analysis by gas-liquid chromatography were: 22.2% galactose and 16.2% mannose--approximately 38% of neutral sugars. Employment of the amino acid methodology for analysis of amino sugars revealed two residues of glucosamine per molecule of the allergen. Hydrolyses with trypsin, alpha-chymotrypsin and type VII protease were tested for sequence studies. Trypsin was considered a suitable enzyme for such purpose.
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PMID:Partial characterization of RC-13, a homogeneous fraction isolated from castor bean allergens (CB-1A). 345 21

Two species of T-kininogen which release T-kinin (Ile-Ser-bradykinin) have been purified from plasma of rats treated with Freund's complete adjuvant. The molecular weight was estimated to be 69,000 for either T-kininogen I and II by SDS-polyacrylamide gel electrophoresis. Trypsin released one mole of T-kinin from one mole of either T-kininogen, but glandular kallikrein, including rat urinary and rat submandibular gland kallikreins and human urinary kallikrein, did not release any kinin from T-kininogens. Cathepsin D, which was purified from rat liver, released T-kinin from T-kininogens at pH 4.0. These results indicate that rat plasma contains two types of T-kininogen which differ from high molecular weight and low molecular weight kininogens.
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PMID:Isolation and properties of two rat plasma T-kininogens. 354 20

The interaction between thyroid microsomal autoantibodies and thyroid microsomal antigen/thyroid peroxidase (TPO) has been studied using both intact antigen preparations and their water-soluble trypsin fragments. In an analysis of sera from 30 patients with Graves' or Hashimoto's diseases, microsomal antibodies showed similar reactivity towards trypsin fragments (with TPO activity) and intact detergent (sodium deoxycholate, DOC)-solubilized human microsomal antigen preparations (r = 0.96). This raised the possibility that both the peroxidase-active site and the major autoantigenic site(s) of microsomal antigen were present on the same trypsin fragments. Studies with porcine TPO showed that only a few sera contained microsomal antibodies which cross-reacted strongly with the porcine preparations. Further analysis was carried out by immunoprecipitation of 125I-labelled microsomal antigen followed by SDS-PAGE and autoradiography. These studies suggest that intact human microsomal antigen (a single-chain protein with Mr = 110,000) contains an intrachain loop of amino acids formed by a disulphide bridge. Trypsin treatment cleaves the antigen close to its transmembrane section and releases a water-soluble fragment (Mr = 100,000), containing the intact disulphide-linked loop of amino acids. Further trypsin action causes cleavage of the peptide bonds within the loop in some preparations. Consequently, three major water-soluble trypsin fragments (Mr = 100,000, 73,000 and 68,000) are formed all of which contain an intact disulphide bridge and have microsomal antibody binding activities. The integrity of the disulphide bridge in intact antigen/TPO preparations and their trypsin fragments is essential for autoantibody binding activity.
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PMID:Structure-activity analysis of microsomal antigen/thyroid peroxidase. 366 90

Peanut agglutinin (PNA), a lectin that binds D-galactose-beta (1----3) N-acetyl-D-galactosamine disaccharide linkages, selectively labels cone photoreceptors in the retinae of a variety of species. PNA binds consistently to domains of the interphotoreceptor matrix associated with cone, but not rod, inner and outer segments, to cone cell body and axonal membranes, to cone synaptic pedicles, and to portions of the inner plexiform layer. In order to begin the characterization of the molecular species responsible for cone-specific PNA binding, chick, turkey, rat, dog, pig, monkey, and human retinal extracts were separated by SDS-polyacrylamide gel electrophoresis and probed with peroxidase-conjugated PNA. The results reveal the presence of six major groups of PNA-binding glycoproteins ranging from 30 to 88 kilodaltons. Most of these are shared by the seven species examined; however, some interspecies variation is present. Three groups, designated GP39/40, GP42/45, and GP60, are the most intensely labeled by PNA and are common to all species analyzed, while groups GP29/31 and GP88 are less intensely labeled and are present in most but not all of the species investigated. Labeling of the GP54 group is variable but is most consistently associated with extracts of rat and pig retinae. Trypsin treatment, which results in the loss of cone-associated PNA binding in the interphotoreceptor matrix, causes a visually detectable reduction in three of the six groups of PNA-binding glycoproteins in porcine retinal extracts. Of these, GP54 is the most sensitive, being undetectable on PNA-stained blots after only 5 minutes of enzyme exposure; GP88 and GP45 are less sensitive but both are markedly reduced after 15 minutes of trypsinization. Trypsin-sensitive molecules thus may be involved in the establishment of the cone-specific domains of interphotoreceptor matrix identified by PNA binding. These, as well as the other groups of PNA-binding molecules, are being utilized to develop more specific immunologic probes with which to further study of their distribution and function.
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PMID:Biochemical characterization of the major peanut-agglutinin-binding glycoproteins in vertebrate retinae. 374 5

Very low density lipoproteins (VLDL) from normolipidemic subjects were able to bind to the cultured human skin fibroblasts almost as efficiently as low density lipoproteins (LDL). The rate of esterification of cholesterol in the fibroblasts was enhanced by VLDL to the same extent as by LDL. Trypsin treatment of VLDL abolished the binding capacity completely. When trypsin-treated VLDL was partially delipidated with heptane, part of the binding capacity to the fibroblasts was restored. SDS polyacrylamide gel electrophoresis showed that apolipoprotein E (apo E) in VLDL was digested completely by trypsin. Although normal VLDL are recognized by the cells through apolipoprotein E, the major apoprotein of VLDL, that is apolipoprotein B (apo B), is not functional unless the core triglycerides are removed. In contrast to the previous reports which indicate that only hypertriglyceridemic VLDL and not normal VLDL interact with fibroblast receptors, our results clearly show that VLDL from normolipidemic subjects can also bind to these receptors.
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PMID:Interaction of normolipidemic very low density lipoproteins with receptors in human skin fibroblasts. 385 63

Human placental microvillous alkaline phosphatase (M-PLAP) was extracted from microvilli either by butanol extraction or subtilisin proteolysis. The data indicate that subtilisin cleavage of PLAP removes a membrane-binding domain of approximately 2000 molecular weight, leaving the catalytic site intact and the protein in solution. Sequencing studies on the N-terminal 13 amino acids of both the subtilisin-cleaved and uncleaved forms of M-PLAP indicate that the enzyme is anchored to the plasma membranes by its carboxy-terminus. The N-terminal 13 amino acids of A-PLAP were the same as those of M-PLAP. Trypsin solubilization failed to release M-PLAP from these membranes and it appears to cleave a portion of molecular weight of about 9K from the amino terminus, leaving an enzymatically active portion of PLAP associated with the membrane. On SDS gels, subtilisin-cleaved M-PLAP showed an apparent dimeric molecular size larger than that of the original uncleaved enzyme, presumably due to the generation of a less compact conformational state. On starch gels, cleaved M-PLAP showed a single zone of enzyme activity with a mobility sightly greater than that of A-PLAP, which did not require the presence of Triton X-100 to enter the gel. Variations in the apparent molecular sizes of the different allelic forms of PLAP were also observed.
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PMID:Placental alkaline phosphatase integrates via its carboxy-terminus into the microvillous membrane: its allotypes differ in conformation. 390 24

The platelet aggregating component from murine 15091A mammary adenocarcinoma cells was purified by solubilization of activity with CHAPS (3-[(3-cholidamidopropyl)-dimethylammonio]-1-propane sulfonate), fractionation with ammonium sulfate, ion exchange chromatography on DEAE cellulose, and hydrophobic interaction chromatography on dodecyl agarose. A purification of 90-100 fold over the initial cell homogenate was achieved. SDS-PAGE of the purified material resulted in a single major band with a molecular weight of 51,000 +/- 2,000. Procoagulant activity was found to copurify with platelet aggregating activity. Reconstitution with phospholipids was necessary to obtain platelet aggregating activity and procoagulant activity. Trypsin abolished both platelet aggregating and procoagulant activities. The irreversible proteinase inhibitors phenylmethylsulfonyl fluoride, N alpha-p-tosyl-L-lysine chloromethyl ketone, iodoacetamide or phenanthroline had no effect on platelet aggregating or procoagulant activities. Platelet aggregation induced by this material was inhibited by low concentrations of the specific irreversible thrombin inhibitors, dansylarginine N-(3-ethyl-1, 5-pentanediyl) amide and D-phenylalanyl-L-prolyl-L-arginine chloromethyl ketone. This is the first report of copurification of tumor cell platelet aggregating and coagulating activities.
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PMID:Purification and characterization of platelet aggregating activity from tumor cells: copurification with procoagulant activity. 397 74

Rat liver acetyl-CoA carboxylase has been purified to homogeneity by a new method involving polyethylene glycol precipitation, and DEAE and Sepharose 4B chromatography. The final product displays a single band on SDS polyacrylamide gel electrophoresis of estimated molecular weight 240,000. This material contains 5.5 +/- 0.3 moles of alkali-labile phosphate per subunit and has a specific activity of 1.2 +/- 0.2 units per mg protein. As compared to previous purification procedures for the liver enzyme, this product has a higher phosphate content, lower specific activity, and an absence of major proteolysis. Trypsin digestion of 32P-labeled acetyl-CoA carboxylase from hepatocytes reveals that the 32P-labeled phosphorylation sites are extremely labile to proteolytic digestion. Potential modification of isolated liver acetyl-CoA carboxylase by proteolysis and/or dephosphorylation must be ascertained prior to in vitro enzymatic studies.
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PMID:A new method for the isolation of rat liver acetyl-CoA carboxylase. 611 63

Encephalomyocarditis (EMC) and influenza viruses attach to human erythrocytes causing haemagglutination of the cells. Sialoglycoproteins, containing predominantly glycophorin A, from these cells behave as soluble virus receptors and inhibit haemagglutination by both viruses. Removal of 43% of the sialic acid from erythrocytes with neuraminidase prevented their haemagglutination by EMC virus loss of 40% of glycophorin sialic acid destroyed its inhibitory properties against this virus. However, about 80% of the sialic acid had to be removed from erythrocytes or from glycophorin to achieve the same results for influenza virus. Trypsin treatment of erythrocytes or glycophorin had little effect on haemagglutination or inhibition involving either virus, although the glycopeptides released contain up to 70% of the total sialic acid, and despite the fact that glycophorin was drastically reduced in size as shown by SDS--polyacrylamide gel electrophoresis. It is concluded that not all of the sialic acid present in erythrocyte sialoglycoprotein receptors is involved in attachment of EMC or influenza viruses and that the attachment sites on erythrocytes for these viruses are not identical.
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PMID:Effect of enzymes on the attachment of influenza and encephalomyocarditis viruses to erythrocytes. 627 Feb 64

Alpha 1 protease inhibitor antigen was identified in the culture medium of the human ascites hepatoma cell line SK-HEP-1. Trypsin inhibitory activity and alpha 1 Pl antigen accumulated in serum-free medium concomitantly over a period of several days. Radioactive alpha 1 Pl antigen was detected in conditioned medium from cultures supplemented with 35S-L-methionine, indicating a synthesis and release of the protein. Alpha 1 Pl antigen in conditioned medium appeared to be antigenically identical to that in human plasma, and the newly synthesized (radiolabeled) antigen co-migrated with plasma, alpha 1 Pl after immunoelectrophoresis or SDS-polyacrylamide gel electrophoresis. Moreover, evidence is presented that the synthesized inhibitor exhibits functional activity, since the 35S-labeled alpha 1 Pl in conditioned medium complexes with trypsin. We conclude that SK-HEP-1 cells in culture produce functionally active alpha 1 Pl which may be identical to that in plasma.
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PMID:Functional alpha 1 protease inhibitor produced by a human hepatoma cell line. 627 80


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