Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q07644 (polypeptide)
 72,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The topology of several of the cytoplasmically made subunits of beef heart cytochrome c oxidase has been determined by protease digestion of oriented membrane preparations, using subunit-specific antibodies to identify cleavage products. Reconstituted vesicles of cytochrome c oxidase and asolectin were used as a vesicle preparation with the C domain of the enzyme available for protease digestion. Submitochondrial particles were used as vesicles with the M domain outermost. Trypsin and/or proteinase K cleaved polypeptides CIV, ASA, AED, STA, and IHQ. Cleavage of CIV, STA, and IHQ was from the M domains only and involved the removal of a fragment from the N-terminus in each case. Polypeptide AED was cleaved from the C side in the N-terminal part, while ASA was cleaved from both the C and M domains. Polypeptide fragments were electroblotted from polyacrylamide gels onto derivatized glass paper and sites of proteolytic cleavage determined by N-terminal sequence analysis.
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PMID:Orientation of the cytoplasmically made subunits of beef heart cytochrome c oxidase determined by protease digestion and antibody binding experiments. 283 91

The possible involvement of vasoactive intestinal polypeptide (VIP) in the non-adrenergic non-cholinergic (NANC) relaxation of the cat gastric fundus was studied in circular and longitudinal muscle strips. Cumulative transmural stimulation induced a frequency-dependent relaxation, while cumulative administration of VIP induced a concentration-dependent relaxation. Tetrodotoxin almost completely antagonized the relaxation induced by transmural stimulation (1 Hz), but did not influence the relaxation induced by VIP (10(-7) M); the latter was not influenced by hexamethonium or propranolol plus phentolamine. Trypsin (30 min incubation) and VIP antiserum (1 h incubation) prevented the relaxation induced by VIP and reduced that induced by transmural stimulation, but did not influence the relaxation induced by isopropylnoradrenaline. Two putative VIP receptor antagonists, [AcTyr1]hGRF-(1-40)OH and [4Cl-D-Phe6,Leu17]VIP, did not influence the relaxation induced by VIP or transmural stimulation. These results are compatible with the hypothesis that VIP is involved in the NANC relaxation of the cat gastric fundus, although participation of a non-VIP component cannot be excluded.
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PMID:Comparison of the effect of vasoactive intestinal polypeptide and non-adrenergic non-cholinergic neurone stimulation in the cat gastric fundus. 285 Feb 4

The synthesis of lauroyl sucrose capable of solubilizing 100% of beta-adrenergic receptors from bovine cerebellum membranes has been carried out. The preparative procedure for isolation of homogeneous beta-adrenergic receptors including affinity chromatography on the novel support, oxprenolol-Sepharose, is described. According to SDS-PAAG electrophoresis data, the Mr value for the beta-adrenergic receptor is 61 kD. The purified beta-adrenergic receptor can interact with the purified GTP-binding regulatory protein of adenylate cyclase (Gs) after their reconstitution into liposomes. Trypsin treatment of the purified receptor does not interfere with its functional properties, nor does it change the hydrodynamic parameters under non-denaturing conditions despite the fact that the polypeptide chain of the receptor is cleaved by trypsin.
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PMID:[Isolation of a homogeneous functionally active beta-adrenergic receptor from bovine cerebellum using lauroyl sucrose. Effect of trypsin on receptor activity]. 285 8

Trypsin and cyanogen bromide were used for cleavage of the OSCP preparations. The peptide mixtures thus formed were separated into individual components by a combination of various chromatographic procedures: gel filtration, ion exchange and paper chromatography, as well as reversed-phase HPLC. As a result, 31 tryptic peptides and 9 out of 10 possible cyanogen bromide peptides were isolated. Determination of the amino acid sequences of these peptide allowed the alignment of cyanogen bromide fragments in the polypeptide chain that shed light on the "architecture" of the protein molecule as a whole. It also afforded the overlappings for tryptic peptides, 16 in the N-terminal and 8 in the C-terminal portions of the molecule.
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PMID:[Primary structure of the OSCP protein that confers sensitivity to oligomycin on the mitochondrial H+-ATPase complex. I. Tryptic and cyanogen bromide peptides]. 286 Sep 9

The isolated and membrane-bound forms of the adenosinetriphosphatase of Escherichia coli (ECF1 and ECF1F0, respectively) have been reacted with two lysine-specific reagents, sodium hexadecyl 4-[3H]formylphenyl phosphate (HFPP) and sodium methyl 4-[3H]formylphenyl phosphate (MFPP), and with the photoreactive reagent 1,2-[3H]dipalmitoyl-sn-glycerol 3-[[[(4-azido-2-nitrophenyl)amino]ethyl]-phosphate] (arylazidoPE). HFPP and arylazidoPE are amphipathic molecules, inserting by their hexadecyl moieties (one and two chains, respectively) into the lipid bilayer, with the reactive groups intercalated among the phospholipid head groups. MFPP is the water-soluble analogue of HFPP. The labeling patterns of ECF1F0 obtained with HFPP and arylazidoPE were very similar; in both cases the a and b subunits of the F0 part were the most heavily labeled polypeptides of the complex. Models of subunit a, arranged in six transmembrane helices, place most of the lysines in the head-group region, available for reaction with HFPP. Subunits alpha and beta of the ECF1 part were very poorly labeled in comparison to the a and b subunits, together incorporating only 4% as much HFPP and 7.5% as much arylazidoPE as the two F0 subunits together on a protein mass basis. Trypsin cleavage studies localized any labeling of the alpha subunit by arylazidoPE to the N-terminal 15 residues of this polypeptide. When MFPP was used, the alpha and beta subunits were very much more reacted than the F0 subunits. This implies that most of the mass of the alpha and beta subunits in ECF1F0 is above the membrane and not in contact with the bilayer surface.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Labeling of the ATP synthase of Escherichia coli from the head-group region of the lipid bilayer. 289 29

The transforming growth factor-beta (TGF-beta) receptor type III is a low abundance cell surface component that binds TGF-beta 1 and TGF-beta 2 with high affinity and specificity, and is present in many mammalian and avian cell types. Type III TGF-beta receptors affinity-labeled with 125I-TGF-beta migrate in sodium dodecyl sulfate-polyacrylamide electrophoresis gels as diffuse species of 250-350 kDa. Here we show that type III receptors deglycosylated by the action of trifluoromethanesulfonic acid yield affinity-labeled receptor cores of 110-130 kDa. This marked decrease in molecular weight is also achieved by combined treatment of type III receptors with heparitinase and chondroitinase ABC. Digestion of receptor-linked glycosaminoglycans by treatment of intact cell monolayers with heparitinase and chondroitinase does not prevent TGF-beta binding to the type III receptor core polypeptide and does not release the receptor polypeptide from the membrane. The type III TGF-beta receptor binds tightly to DEAE-Sephacel and coelutes with cellular proteoglycans at a characteristically high salt concentration. Thus, the type III TGF-beta receptor has the properties of a membrane proteoglycan that carries heparan and chondroitin sulfate glycosaminoglycan chains. The binding site for TGF-beta appears to reside in the 100-120-kDa core polypeptide of this receptor. The type III receptor is highly sensitive to cleavage by trypsin. Trypsin action releases the glycosaminoglycan-containing domain of the receptor leaving a 60-kDa membrane-associated domain that contains the cross-linked ligand. A model for the domain structure of the TGF-beta receptor type III is proposed based on these results.
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PMID:The transforming growth factor-beta receptor type III is a membrane proteoglycan. Domain structure of the receptor. 290 57

A large-scale procedure for the isolation of complement receptor type 1 (CR1, the C3b receptor) from human erythrocytes is described. Two of the four known phenotypes of CR1 are detectable in the isolated material. Amino acid and hexosamine analysis of the A phenotype (Mr 240 000) indicates a polypeptide chain length of about 2030 amino acids and a carbohydrate content of 8%. Both N- and O-linked sugars appear to be present. Trypsin digestion of isolated CR1 shows that it is degraded rapidly and extensively, and no stable products of Mr greater than 25000 are found. The ability of the receptor to bind to solid-phase ligand is destroyed after a single cleavage by trypsin. The capacity of the receptor to act as a cofactor for Factor I-mediated cleavage of soluble C3b is, however, only gradually decreased by proteolysis, and 30% of this activity remains after extensive degradation. The same pattern of loss of binding to solid-phase ligand, with partial retention of interaction with soluble ligand, is also characteristic of the complement proteins Factor H and C4bp, which are functionally related to CR1.
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PMID:Large-scale isolation of complement receptor type 1 (CR1) from human erythrocytes. Proteolytic fragmentation studies. 293 34

We have isolated cDNA clones encoding the entire sequence of the bovine 46 kd cation-dependent mannose 6-phosphate (CD Man-6-P) receptor. Translation of CD Man-6-P receptor mRNA in Xenopus laevis oocytes results in a protein that binds specifically to phosphomannan-Sepharose, thus demonstrating that our cDNA clones encode a functional receptor. The deduced 279 amino acid sequence reveals a single polypeptide chain that contains a putative signal sequence and a transmembrane domain. Trypsin digestion of microsomal membranes containing the receptor and the location of the five potential N-linked glycosylation sites indicate that the receptor is a transmembrane protein with an extracytoplasmic amino terminus. This extracytoplasmic domain is homologous to the approximately 145 amino acid long repeating domains present in the 215 kd cation-independent Man-6-P receptor.
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PMID:46 kd mannose 6-phosphate receptor: cloning, expression, and homology to the 215 kd mannose 6-phosphate receptor. 295 52

Eukaryotic plasma membranes contain three Ca-transporting systems: a Ca channel, an ATPase, and an Na/Ca exchanger. The ATPase is high-affinity, low-capacity system, which continuously pumps Ca out of cells. The Na/Ca exchanger is a low-affinity, high-capacity system, which is particularly active in excitable cells. The exchanger probably functions in both the Ca efflux and influx directions. The Ca-ATPase is a single polypeptide of Mr 138 kD, which is activated by calmodulin or, in its absence, by acidic phospholipids, polyunsaturated fatty acids, and limited proteolytic treatments. Trypsin produces a number of fragments, some of which (Mr 90, 85, and 81 kD) function as ATPases and transport Ca across reconstituted bilayer membranes. Trypsin proteolysis in the presence of different effectors has permitted us to locate the calmodulin-interacting domain of the enzyme in a 9-kD peripheral sequence that consists of a 4-kD calmodulin-binding subdomain and a subdomain of Mr 5 kD, which is essential for the expression of calmodulin stimulation. The Na/Ca exchanger of plasma membranes has not yet been identified with certainty. On the basis of purification attempts using different approaches, probable Mr's of 82, 70, or 33 kD have been proposed. Antibodies raised against the 33-kD protein partially inhibit the exchange activity of heart sarcolemma vesicles. They interact with the 33-kD protein, but also, under nonreducing conditions, with proteins of Mr approximately 70 and approximately 140 kD. Under reducing conditions, the reactivity with the latter component disappears. It is suggested that the monomeric Mr of the exchanger is 33 kD, and that intermolecular disulfide bridges associate monomers into dimeric and tetrameric forms.
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PMID:The plasma membrane in the control of the signaling function of calcium. 297 49

In vitro proteolytic cleavage of the Gazdar murine sarcoma virus (Gz-MuSV) p65gag polypeptide (Gz-p65gag) was facilitated by detergent-disrupted Moloney murine leukaemia virus (Mo-MuLV). Incubation of radioactively labelled Gz-p65gag in the presence of unlabelled Mo-MuLV under optimal conditions resulted in the cleavage of Gz-p65gag to proteins of 40000 (P40) and 25000 (P25) Mr. P40 and P25 appeared to be similar in both mobility and antigenicity to Mo-MuLV intermediates, Pr40gag and Pr25gag, previously found in infected cells. Additional proteins of 30000 (Gz-p30), 15000 (Gz-p12), 12000 (Gz-p15) and 10000 (Gzp10) Mr were also generated upon cleavage of Gz-p65gag and contained antigenic determinants of Mo-MuLV structural proteins p30, pp12, p15 and p10, respectively. Both detergent-disrupted Mo-MuLV and Rauscher murine leukaemia virus produced similar cleavage profiles. Trypsin and detergent-disrupted mouse mammary tumour virus generated cleavage patterns very different from that produced by Mo-MuLV. Both visual and quantitative time studies of the reaction indicated that P40 gave rise to Gz-p30 and Gz-p10. Tryptic peptide mapping of Gz-p65gag and its cleavage products supported the results obtained from both immunoprecipitation studies with anti-gag sera and the kinetics of cleavage of Gz-p65gag. Both Mo-MuLV Pr65gag and Gz-p65gag were found to be very similar in primary sequence as judged by peptide mapping. P40 produced tryptic peptides that co-migrated with Mo-MuLV p30 peptides; P25 contained tryptic peptides that were also found in Mo-MuLV p15. Gz-p30 and Gz-p15 contained the tryptic peptides of Mo-MuLV p30 and p15, respectively, that were found in P40 and P25. The Gz-p10 fraction contained a tryptic peptide that was also found in P40, but not p30. These results provide good evidence that the protease packaged within Mo-MuLV can cleave, in vitro, the gag-related polyprotein of Gz-MuSV in a manner very similar to the processing of Mo-MuLV Pr65gag in infected cell culture systems.
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PMID:Further characterization of the in vitro products generated by proteolytic cleavage of Gazdar murine sarcoma virus p65gag. 298 63


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