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

In the stroma-free hemolysate of rabbit reticulocytes there exists a respiratory inhibitor (RF) of protein nature. It could be purified by the following procedure: (NH4)2SO4-precipitation leads to DEAE-Sephadex A-50-chromatography leads to isoelectric focusing leads to gelfiltration on Sephadex G-200. In addition to the activity the identity of the inhibitor could be proved immunologically at all steps of the purification. A molecular weight of about 80,000 was determined by gelelectrophoresis in the SDS-mercaptoethanol-system. The protein has an IP of 5.55--5.65 and consists of one polypeptide chain. This could be shown both by SDS-gelelectrophoresis and by estimation of only one N-terminal amino acid residue (glycine). Only after oxidation with performic acid the amino acid analysis of the protein gives reproducible values. The sum of weight-% is about 80 (without Tyr). The polarity of the protein with 41 mol-% agrees with the polarity of soluble globular proteins investigated by other authors. Acid hydrolysis without preceeding performic acid oxidation gives a sum of amino acid residues of only 35--45 weight-%, the glycoprotein nature of the inhibitor could be shown by staining the SDS-gels with Schiff's reagents and by carbohydrate determination with anthrone reagent.
 ...
PMID:[Purification and characterization of the respiratory inhibitor RF from rabbit reticulocytes]. 59 53

Synaptic vesicles were isolated from adult bovine cortical gray matter by differential centrifugation and membrane filtration of a hypoosmotically lysed crude mitochondrial fraction. Vesicle preparations were analyzed for purity by electron microscopy and enzyme assays. Polyacrylamide gel electrophoresis of SDS-solubilized and 2-mercaptoethanol-reduced vesicle membrane proteins revealed 4 major proteins with molecular weights ranging from 17,000 to 60,000, and about 10 minor proteins with molecular weights up to 170,000. The protein profile of the Triton X-100-extracted vesicle membranes was less complex, with 1 major protein and 5 minor bands. The major protein of the Triton extract was identified as a glycoprotein with a molecular weight of 45,000. Two additional minor PAS-positive bands were seen, with molecular weights of 78,000 and 95,000.
 ...
PMID:Membrane protein and glycoprotein composition of beef brain synaptic vesicles. 59

A microsomal fraction containing high amounts of plasma membrane has been isolated from human tonsillar lymphocytes. The subcellular fractions were characterized on the basis of their chemical composition and enzyme activities. A glycoprotein fraction solubilized by lithium-diiodo-salicylate (LIS) was purified by ion-exchange chromatography. The purified glycoprotein was analyzed by various methods and its carbohydrate content was determined. The glycoprotein contained large amounts of hexoses and sialic acid and this fraction represented 3--4% of the whole plasma membrane protein. The fraction was shown to consist of three individual proteins (4 X 10(4), 4.6 X 10(4) and 4.8 X 10(4) daltons) determined by SDS-polyacrylamide gel electrophoresis.
 ...
PMID:Studies on human tonsillar lymphocyte membranes. I. Isolation and characterization of a membraneous glycoprotein fraction from human lymphocytes. 60 73

An inhibitory factor obtained from mature human granulocytes which suppresses granulocyte and monocyte-macrophage colony formation by an action on the endogenous colony stimulating factor-producing cells has been partially purified and characterized. The methods for purification consisted of a combination of ultracentrifugation, DEAE-Sephadex chromatography, SDS polyacrylamide gel electrophoresis and isoelectric focusing. The material had a molecular weight range of 102--128 000 and an isoelectric point between pH 6.2 and 6.4. The inhibitory factor was found to be heat stable and glycoprotein in nature.
 ...
PMID:Isolation of a granulocyte colony inhibitory factor derived from human polymorphonuclear neutrophils. 63 90

The structural polypeptides of two strains of measles virus grown in Vero cells were analysed in SDS-PAGE slab gels. Six major polypeptides were identified with mol. wt. of 79000, 72000, 60000, 43000, 40000 and 36000. The largest polypeptide was sensitive to trypsin digestion and was the dominant glycosylated polypeptide identified when the virus was grown in medium containing 3H-fucose or 3H-glucosamine or when the virus was treated with galactose oxidase and labelled with 3H-sodium borohydride. It is concluded that the 79000 mol. wt. polypeptide represents the haemagglutinin. Treatment with non-ionic detergent removed this polypeptide and also the 40000 mol. wt. polypeptide from the virus envelope. The 40000 mol. wt. polypeptide is probably associated with haemolysin and cell fusion activities and is analogous to the F1 of paramyxoviruses. A polypeptide of mol. wt. approx. 20000 detected after glycoprotein labelling may represent the F2 of measles virus. The 43000 mol. wt. polypeptide co-migrates with cellular actin and is the only major measles polypeptide that is heavily labelled when the virus is grown on Vero cells prelabelled with 35S-methionine. Thus it may represent cellular actin incorporated into the virus during maturation. The quantity of the 72000 mol. wt. polypeptide relative to the other major polypeptides varied considerably in different virus preparations. The role of the polypeptide could not be defined. By analogy with previously published data the 60000 and 36000 mol. wt. polypeptides are inferred to represent nucleocapsid and membrane proteins, respectively.
 ...
PMID:Structural polypeptides of measles virus. 65 Jan 74

C4-binding protein (C4-bp), a new component of the complement system, was isolated from human plasma by precipitation with polyethyleneglycol, followed by chromatography on ion exchangers. C4-bp was identified on sodium dodecyl- sulfate polyacrylamide gel electrophoresis (SDS-PAGE) by two independent criteria: its ability to bind to C4b, and immunoprecipitation with a monospecificantiserum. Purified C4-bp is a 10.7 s glycoprotein. It consists of several disulfide bonded subunits of mol wt 70,000 daltons. Under nonreducing conditions, its mol wt has been estimated on SDS-PAGE as 540- 590,000 daltons. C4-bp moves as a slow B-globulin at pH 8.6 in the absence of free divalent cations, but when the buffers contain Ca(++)-lactate, C4-bp is a gamma globulin. Purified C4-bp binds to purified C4b. The reaction proceeds in the presence or absence of divalent cations and is not inhibited by diisopropylfluorophosphate. The C4b/C4-bp complexes have sedimentation coefficients between 15 and 17 s on sucrose gradient ultracentrifugation, and can be readily identified by crossed immunoelectrophoresis (CIE). The complexes move faster toward the anode than either protein. C4-bp is multivalent. Saturation is reached at molecular ratios of C4b/C4- bp of between 4 and 5. The interaction between C4b and C4-bp may complicate the electrophoretic patterns of these proteins in normal human serum, if the complement system is activated before or during the run. However, in EDTA-plasma, native C4 and C4-bp do not form stable complexes and can be identified in separate peaks after CIE.
 ...
PMID:Human C4-binding protein. I. Isolation and characterization. 67 Aug 86

Of the three major proteins associated with the rabies virus membrane, only the glycoprotein (G-protein) was found to be located on the external surface of the viral membrane. A minor glycoprotein (gp 50) detected by SDS-polyacrylamide gel electrophoresis (PAGE) of rabies virus appeared to be a breakdown product of the G-protein. Glycoprotein prepared by treatment of rabies virus with Triton X100 and purified by isoelectric focusing was found to be homogeneous with respect to size and isoelectric point. The apparent molecular weight of this component isolated under nondenaturing conditions is approximately 400,000 daltons. The same material analyzed by PAGE was found to be comprised solely of polypeptide chains of the G-protein (MW 80,000 daltons). Therefore, the Triton X100-released material represents homopolymers of the G-protein. The purified rabies virus glycoprotein (G) is only structural protein of the virus that induces the formation of virus-neutralizing antibodies and which confers immunity to animals. The total protective activity of the virus was recovered in the purified G protein preparation. The protective activity of G protein increased with purification : 9 ng of G protein was required to protect 50% of the mice as compared to 1.63 microgram of the virus. The number of oligosaccharide side chains on rabies virus glycoprotein was investigated. Analysis of glycopeptides obtained by protease digestion of desialated glycoprotein revealed three discrete glycopeptides. Comparison of the protease digestion products from desialated and from untreated glycoprotein indicated a heterogeneity among the glycopeptides in the sialic acid content. Two major tryptic glycopeptides were isolated from desialated rabies virus glycoprotein and were analyzed after protease digestion; one contained two oligosaccharide side chains and the other contained a single oligosaccharide side chain.
 ...
PMID:Structure and function of rabies virus glycoprotein. 68 Apr 1

Rabbit exudate-derived PMN were homogenized and the cell membranes isolated on a two-phase aqueous system. Glycoproteins were extracted from cell membranes with lithium diiodosalicylate. SDS polyacrylamide gel electrophoretic analysis showed a consistent pattern of three major glycoprotein entities. Cells radioiodinated supravitally showed most of the radioactivity associated with larger glycoprotein entities whereas PMN membranes radiolabeled after isolation yielded a single major peak of radioactivity associated with a much smaller protein entity. Heterologous antisera against rabbit PMN, PMN membranes, and membrane glycoproteins were all cytotoxic for PMN in the presence of complement, and all bound to the PMN surface as demonstrated with immunocolloidal gold on electron microscopy. The data suggest that one or more glycoprotein entities are membrane-associated ectoglycoproteins which can be radiolabeled supravitally.
 ...
PMID:Neutrophilic leukocyte membrane proteins. I. Isolation. 68 Sep 53

Human platelet plasma membrane glycoprotein I with an apparent molecular weight of approximately 150,000 has been shown to be one of the proteins retained by thrombin immobilized on Sepharose 4B. The retained glycoprotein has been recovered by sodium dodecyl sulfate elution and characterized by SDS polyacrylamide gel electrophoresis in the presence of 2-mercaptoethanol.
 ...
PMID:Affinity chromatographic demonstration of a thrombin binding protein from the platelet plasma membrane. 69 35

In contrast to other studies, our results demonstrate that low concentration of trypsin degrades a high proportion of proteolipid from CNS myelin. The Wolfgram protein and BP are vulnerable and completely lost on trypsinolysis, perhaps accounting for some of the peptides retained by the myelin. In PNS myelin, the major PO protein, a hydrophobic glycoprotein, is readily degraded to a stable 18,000--19,000 molecular weight unit, referred to as TPO protein, still retaining the carbohydrate unit which probably exists as a nonasaccharide grouping. Production of the TPO glycoprotein results from cleavage of a lysinyl-methionine or arginyl-methionine linkage probably found approximately 80--100 residues from the NH2-terminal isoleucine of the PO molecule. This linkage must be especially accessible to trypsin since the TPO protein is also generated in high yield when isolated PO protein is treated with trypsin in solution for 0.5 hours. Further incubation for 24 hours fully degrades the TPO protein to over 20 tryptic peptides, shown by peptide mapping, unlike the situation in myelin where the TPO unit is stable and resists further proteolysis. The TPO unit is also produced when PO protein is treated with BrCN. The PO protein contains 3 methionine residues but presumably the methionine residue in the trypsin-sensitive region is crucial; cleavage leads to the same TPO unit minus NH2-terminal methionine. Another methionine residue also exists in the TPO protein but it may be resistant to BrCN cleavage or else occupy a near-end position. Other proteins were also identified on PAGE of trypsinized PNS myelin: albumin, P2 protein, and PO protein. Albumin and P2 protein were identified in the acidic extract by reaction with specific antibody. The PO protein was isolated; it moved similarly to standard protein on SDS-PAGE and gave the appropriate amino acid analysis. However, it cannot be determined at this time whether a portion of these proteins remains because they are partially inaccessible to trypsin, or else are slightly attacked and thus represent early stages of trypsinolysis. The P2 protein of trypsinized myelin appears to migrate slightly faster than standard P2 protein on PAGE. Further work should clarify this point. Amino acid analysis and sequence data show that the PO protein is particularly hydrophobic, very likely existing in PNS myelin as an amphipathic molecule which penetrates the bilayer but which has a hydrophilic portion exposed. It is this hydrophilic region that contains much lysine, particularly the crucial lysinyl-methionine linkage, that is so trypsin-sensitive. Determination of the amino acid sequence of terminal portions of the isolated PO and TPO proteins serves to firmly establish the PO protein as a unique entity probably exclusive to PNS myelin. It can be concluded that the study of trypsin activity toward PNS myelin has made possible a new understanding of how proteins are positioned in the membrane, and provided valuable insight into the PO protein.
 ...
PMID:The action of trypsin on central and peripheral nerve myelin. 69 76


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>