Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Genetic polymorphism in a mucin of the human milk fat globule arises from variable numbers of a tandemly repeated amino acid sequence. As a consequence, the gene from each parent expresses a variable-sized protein. This is manifest on SDS gels in the form of either one or, more often, two protein bands, which differ among individuals in mobility. Evidence of such polymorphism in the bovine mucin, PAS-I, was first obtained from Holstein milk samples. The objective of this study was to evaluate the other major dairy breeds for polymorphism of their PAS-I. Milk samples from individual Jerseys, Guernseys, Ayrshires, and Brown Swiss were analyzed by SDS-PAGE. Bands of the mucin varying in number and mobility were seen in samples from all four breeds. In three of the breeds (Ayrshire, Brown Swiss, and Jersey), there was evidence that two alleles for PAS-I may have become predominant, possibly through degeneration in the structure of their tandem repeats, one that gives rise to a faster moving mucin (relative molecular weight 170,000) and the other to a slower form (relative molecular weight 200,000). In contrast, the PAS-I band patterns on SDS gels for both Guernseys and Holsteins were characterized in nearly 50% of samples by two close bands near the 205,000-molecular weight marker. This pattern was never seen in the other three breeds. The findings suggest a genetic kinship among the Ayrshire, Brown Swiss, and Jersey, on the one hand, and between the Holstein and Guernsey, on the other.
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PMID:Genetic polymorphism of the epithelial mucin, PAS-I, in milk samples from the major dairy breeds. 156 76

A monoclonal antibody (A8) to a basement membrane component (TIN antigen), which is associated with autoimmune tubulointerstitial nephritis, was developed and utilized to characterize tissue distribution and properties of TIN antigen by immunofluorescence microscopy and immunoblotting. Results were confirmed with polyclonal goat anti-rabbit and human autoantibodies. TIN antigen was found in basement membranes of kidney cortex, small intestines, skin, and cornea, but was not detected in the renal medulla. Within the kidney cortex proximal tubular basement membrane (TBM) showed the strongest staining. TIN antigen was also detected in Bowman's capsule, distal TBM, peritubular capillaries, and focally in the interstitium, but not in glomerular basement membrane or mesangial matrix. Immunoblotting of SDS-extracted human, rabbit, mouse, and Brown Norway rat TBM with A8 revealed predominantly a 58 kD TIN antigen; however, other reactive components were detected in minor quantities. Bovine TBM contained components of 52 kD, 45 kD and 35 kD in varying concentrations. Immunoblotting of isolated rabbit TIN antigen revealed the major 58 kD component that was characterized previously, and minor components of 300 kD, 175 kD, 160 kD and 50 kD. TIN antigen was not detected in Lewis rat TBM by immunofluorescence or immunoblotting. These studies suggest the following: 1) TIN antigen may be synthesized as a high molecular weight glycoprotein that is processed to smaller forms; 2) it may be covalently associated with other basement membrane components; 3) the antibody reactive epitope may be present on multiple TBM components; and 4) high molecular weight forms may represent aggregates of TIN antigen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Distribution of tubulointerstitial nephritis antigen and evidence for multiple forms. 176 87

Skeletal-muscle sarcoplasmic reticulum (SR) comprises two distinct domains, corresponding to the free membrane of longitudinal SR (LSR) and the junctional membrane region of the terminal cisternae (TC), respectively. The junctional membrane contains the ryanodine receptor (RyR)/Ca(2+)-release channel and additional minor protein components that still require biochemical investigation, in relation to excitation-contraction coupling. Recent findings suggested the involvement in this process of a 170 kDa protein [Kim, Caswell, Talvenheimo & Brandt (1990) Biochemistry 29, 9281-9289], also characterized as a phosphoprotein in junctional TC in independent studies [Chu, Submilla, Inesi, Jay & Campbell (1990) Biochemistry 29, 5899-5905]. We show that this protein is a specific substrate of exogenous cyclic AMP-dependent protein kinase, that it is exposed to the outer surface of intact TC vesicles, and that it co-localizes with the RyR to the junctional membrane. Comparative analysis of LSR and TC subfractions for the 160 kDa glycoprotein sarcalumenin, using Western-blot techniques and specific monoclonal antibodies or concanavalin A as a ligand, revealed that the distribution of this protein within the SR corresponds inversely to both that of the RyR and of the 170 kDa protein. The 170 kDa protein, like sarcalumenin, stains blue with the cationic dye Stains-All and binds 45Ca2+ on blots, but it is uniquely distinguished by its ability to bind 125I-labelled low-density lipoprotein. The similarity of these properties, as well as the pI and solubility properties, to those described for the SR protein, recently purified and cloned and named histidine-rich Ca(2+)-binding protein [HCP; Hofmann, Brown, Lee, Pathak, Anderson & Goldstein (1989) J. Biol. Chem. 264, 8260-8270], makes it very likely that our protein and HCP may indeed be identical. The protein described in the present study differs from sarcalumenin because its migration in SDS/PAGE is accelerated in the presence of Ca2+, a previously reported property of other Ca(2+)-binding proteins [leMaire, Lund, Viel, Champeil & Moller (1989) J. Biol. Chem. 265, 1111-1123], arguing for Ca(2+)-induced protein-conformational changes. Kinase-dependent phosphorylation of our protein is another distinguishing feature, which, although not previously reported for HCP, is consistent with the presence of potential serine/threonine phosphorylation sites in the middle portion of the cloned HCP molecule. The finding that HCP, contrary to early views, selectively binds to the cytoplasmic side of the junctional membrane, together with its newly characterized properties, seem to provide new clues as to a possible role in electromechanical coupling and/or Ca2+ release.
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PMID:Subcellular fractionation to junctional sarcoplasmic reticulum and biochemical characterization of 170 kDa Ca(2+)- and low-density-lipoprotein-binding protein in rabbit skeletal muscle. 187 15

Gp is a major GTP-binding protein of human placenta and platelets [Evans, T., Brown, M. L., Fraser, E. D., & Northup, J. K. (1986) J. Biol. Chem. 261, 7052-7059]. High-affinity guanine nucleotide binding is associated with a polypeptide migrating identically with H-ras on SDS-PAGE. We have characterized the interactions of preparations of purified human placental Gp with guanine nucleotides in detergent solution. Equilibrium binding studies with [35S]GTP gamma S, [3H]Gpp(NH)p, and [3H]GTP identified a single class of sites with a dissociation constant of 10 +/- 1, 153 +/- 61, and 125 +/- 77 nM for the ligands, respectively. These three ligands were mutually competitive with Ki values consistent with the Kd values from direct binding experiments. Competition for the binding of [3H]Gpp(NH)p was used to determine the specificity of the site. Ki values determined from this assay were 14 nM for GTP gamma S, 143 nM for Gpp(NH)p, 3.3 microM for GDP beta S, 69 nM for GTP, and 64 nM for GDP. ATP, ADP, cAMP, cGMP, and NAD+ had no detectable affinity for this site. While the equilibrium binding data fit well to a single class of sites, association kinetics of these ligands were better fit to two rate constants. Dissociation kinetics, however, were not clearly resolved into two rates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Unique guanine nucleotide binding properties of the human placental GTP-binding protein Gp. 212 Dec 70

Previous investigations [Jones, Brown, von Glos & Gaunt (1985) Exp. Cell Res. 156, 31-44] have demonstrated the appearance of a new antigenic determinant (recognized by monoclonal antibody 2D6) on the plasma membrane of rat spermatozoa during post-testicular maturation in the epididymis. Identification of the 2D6 antigen on Western blots from one-dimensional SDS/polyacrylamide gels revealed that it co-migrated with a membrane protein (designated Mr 23,000 antigen) present on testicular and immature germ cells, suggesting that one antigen might be a modified version of the other. In the present work, however, we demonstrate that, although they have similar Mr and are present in soluble and membrane-bound forms, the 2D6 and Mr 23,000 antigens are biochemically and immunologically distinct molecules. The properties of the antigens are described and compared. The Mr 23,000 antigen is present on both testicular and cauda epididymidal spermatozoa, has a pI of 6.1, contains no detectable carbohydrate, is not tissue-specific and is degraded by V8 protease. By contrast, the 2D6 antigen is glycosylated, has a broad pI from 4.5 to 6.1, is tissue- and species-specific and is resistant to digestion with V8 protease. Its role in sperm-egg recognition is discussed.
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PMID:Identification and characterization of the 2D6 and Mr 23,000 antigens on the plasma membrane of rat spermatozoa. 243 64

A guanine-nucleotide-binding protein (G-protein) was purified from cholate extracts of bovine brain membranes by sequential DEAE-Sephacel, Ultrogel AcA-34, heptylamine-Sepharose and Sephadex G-150 chromatography. Guanosine 5'-[gamma-[35S]thio]triphosphate (GTP[35S])-binding activity copurified with a 25,000 Da peptide and a 35,000-36,000 Da protein doublet. Neither pertussis toxin nor cholera toxin catalysed the ADP-ribosylation of a protein associated with the GTP[35S]-binding activity. Photoaffinity labelling of the purified protein with 8-azido[gamma-32P]GTP indicated that the GTP-binding site resides on the 25,000 Da protein. The 35,000-36,000 Da protein doublet was electrophoretically indistinguishable from the beta-subunits of other GTP-binding proteins, and the 36,000 Da protein was recognized by antiserum to oligomeric Gt. The purified protein specifically bound 17.2 nmol of GTP[35S]/mg of protein. The Kd of the binding site for radioligand was approx. 15 nM. The brain GTP-binding protein co-migrated during SDS/polyacrylamide-gel electrophoresis with a GTP-binding protein, named Gp, purified from human placenta [Evans, Brown, Fraser & Northup (1986) J. Biol. Chem. 261, 7052-7059], and cross-reacted with antiserum raised against the placental protein, but not with antiserum raised to brain Go. SDS/polyacrylamide-gel electrophoresis of the brain and placental GTP-binding proteins in the presence of Staphylococcus aureus V8 protease yielded identical peptide maps.
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PMID:Identification and purification from bovine brain of a guanine-nucleotide-binding protein distinct from Gs, Gi and Go. 312 Jun 96

Rat Clq was isolated and purified from normal rat serum by a two-step procedure: affinity chromatography on a human IgG-Sepharose 4B column and Bio-Gel A 5m column chromatography. From 1.8 l of normal serum, the procedure yielded 4.5 mg of homogeneous and hemolytically active rat Clq as shown by three bands of peptide in SDS polyacrylamide gel electrophoresis under reducing conditions and by a single precipitin line between rat Clq and rabbit anti-rat Clq antibody. Rabbit anti-rat Clq antibody prepared by immunizing a rabbit with 225 micrograms of rat Clq was specific as shown by a single precipitin line between the antibody and normal rat serum and rat Clq with complete identity. The amino acid composition of rat Clq was very similar to that of human Clq. The purification procedure also yielded Clq-depleted rat serum which was used with the homogeneous Clq to establish a sensitive hemolytic assay: 4.5-13.5 ng of rat Clq can be reproducibly quantitated. The concentration of Clq in Brown Norway rats was estimated to be 41.5 +/- 3.0 micrograms/ml serum.
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PMID:Rat Clq: isolation and purification from normal serum and development of a sensitive hemolytic assay. 387 81

Oocytes from Xenopus laevis microinjected with RNA isolated from Schistosoma mansoni adult worms translated antigens recognized by sera from infected rats, humans, and from immunized rabbits. The pattern of immunoprecipitated proteins analysed by SDS-polyacrylamide gel electrophoresis was species specific in rats. Serum from infected Fischer rats recognized antigens of 20, 27 and several bands in the 50-60 kDa range whereas serum from infected Brown Norway rats also immunoprecipitated major bands at 29, 43 and 100 kDa. Human infection sera gave a very variable pattern of immunoprecipitation not apparently dependent on the patients' age. At least 20 different antigenic species could be identified ranging from 14 to 150 kDa. Some S. mansoni antigenic proteins could be isolated from the membrane fraction of the oocytes whereas notably the 29 kDa band was present mainly in the soluble fraction. N-Glycosylation of S. mansoni antigens occurred as evidenced by the effects of tunicamycin treatment and concanavalin A binding. A multiple series of bands between 50 and 60 kDa, present in the membrane fraction, were glycosylated and secreted from the oocytes. Monoclonal antibodies to larval stage surface antigens failed to immunoprecipitate oocyte translation products, but sera absorbed with live schistosomula identified at least three putative surface antigens of 100, 43 and 29 kDa. However, the 29 kDa molecule was neither synthesized into membranes, nor secreted from oocytes.
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PMID:Translation of Schistosoma mansoni antigens in Xenopus oocytes microinjected with mRNA from adult worms. 401 Jul 5

The DNA as isolated from duck fibroblasts transformed by a duck-adapted Prague strain of Rous sarcoma virus and used for transfection. Transformed recipient BLEF and DEF cultures exhibited considerable morphological variability. The virus designated daPR-RSV-C morphf was obtained from the culture with fusiform transformation and cloned. The virus retained the ability to induce fusiform transformation, even after 20 passages on chicken fibroblasts. There was a good correlation between focus forming activity of the virus and its tumorigenicity in chickens. The frequency of morphf mutation to another phenotype was less than 10(-3) in cloned virus. Foreign avian embryonic cells transformed by this virus clone had a similar morphological appearance as transformed chicken cells. The clone also retained two additional non-conditional markers - subgroup C specificity and the ability to replicate efficiently in duck cells ("duck adaptation"). Freshly obtained cloned virus was found not to contain a transformation-defective mutant. Such a mutant occurred in the second passage of the virus of DEF where the mutant was isolated. Inoculation of the td mutant into Brown Leghorn embryos gave rise to a sarcoma in one of the 36 examined chickens. However, no transforming virus was detected in the sarcoma. SDS-polyacrylamide gel electrophoresis showed that cloned daPR-RSV-C morphf contained only genomic RNA; its molecular weight 3.08 X 10(6) daltons corresponded to the molecular weight of a non-defective PR-RSV-C used as control.
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PMID:Characterization of a mutant of the Prague strain of Rous sarcoma virus inducing fusiform transformation of avian fibroblasts in vitro. 628 73

Monoclonal antibodies against lymphocyte glycoproteins have been used to identify the membrane molecules which bind peanut (PNA) and Helix pomatia (HPA) agglutinins and cap spontaneously on the uropod of polarized rat and mouse thymocytes. On the basis of co-capping experiments and radiolabelling of isolated glycoproteins after sodium dodecylsulfate polyacrylamide electrophoresis (SDS-PAGE), the major HPA- and PNA-binding sialoglycoprotein (with an apparent molecular weight of about 105 K; (1K = 10(3] 125-135 K after neuraminidase treatment) appears to be identical with the thymocyte glycophorin-like protein described by Brown et al. [11] and to correspond to the spontaneously capping component. Components of the mouse T200 (or rat 'leukocyte common antigen') differentiation antigen group also bind PNA (and partially HPA), but are unable to cap spontaneously. Some similarities in the redistribution behaviour of thymocyte and erythrocyte glycoproteins are discussed.
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PMID:Lectin-binding and spontaneous capping characteristics of the thymocyte glycophorin-like glycoprotein. 660 31


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