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At least 19 recordsLinked to original sources
PubMed1996

Separation of the subtypes of type V collagen molecules, [alpha 1(V)]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V), by chain composition-dependent affinity for heparin: single alpha 1(V) chain shows intermediate heparin affinity between those of the type V collagen subtypes composed of [alpha 1(V)]2 alpha 2(V) and of alpha 1(V) alpha 2(V) alpha 3(V).

The heparin affinities of heat-treated type V collagen alpha-chains and the triple-helical molecules were evaluated in terms of the NaCl concentration required for prevention of binding to a heparin-Sepharose column. After heat treatment, alpha 1(V) chain required approximately two-fold higher NaCl concentration to pass through the column than the other two chains, alpha 2(V) and alpha 3(V). Thus, the heparin affinity of alpha 1(V) may be approximately two-fold higher than those of the other alpha (V)-chains. The type V collagen molecules in triple-helical conformation were separated into two fractions at 170 mM NaCl in 20 mM phosphate buffer, pH 7.2, containing 2 M urea; bound and non-bound. The ratio of the three alpha-chains, alpha 1(V): alpha 2(V): alpha 3(V) was 2 : 1 : 0 and 1 : 1 : 1 in the bound and flow-through fractions, respectively, on analysis by SDS-PAGE. The differential affinity of the two fractions could be accounted for by the number of alpha 1(V) chains in the triple-helical molecule, if these fractions contained triple-helical subtypes with the chain compositions of [alpha 1(V)]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V), respectively. From the comparison of the NaCl concentration required for prevention of the binding, [alpha 1(V)]2, alpha 2(V) had about two-fold higher affinity than alpha 1(V) alpha 2(V) alpha 3(V), and the separated alpha 1(V) chain showed an intermediate affinity. A possible explanation for difference in heparin affinity among the subtypes of molecules and the separated alpha-chains is that the heparin affinity of type V collagen molecule is governed by the number of alpha 1(V) chains contained in the molecule and that steric restraint in a triple-helical conformation weakens the binding of alpha 1(V) chain to heparin.

Animals↗
PubMed1988

Identification of multiple novel polypeptide substrates of the v-src, v-yes, v-fps, v-ros, and v-erb-B oncogenic tyrosine protein kinases utilizing antisera against phosphotyrosine.

Antibodies to phosphotyrosine were used to identify proteins phosphorylated on tyrosine in chicken embryo fibroblasts transformed by the oncogenes, v-src, v-yes, v-fps, v-ros, or v-erb-B. These antibodies allowed detection of a minimum of 50, 44, and 47 bands in immunoblots of cellular lysates from fibroblasts transformed by v-src, v-yes, or v-fps respectively. Eight of these bands were also detected in fibroblasts transformed by v-ros and v-erb-B, suggesting that the cellular transformation induced by v-ros, v-erb-B, v-src, v-yes, and v-fps may be achieved by the phosphorylation of some of the same proteins. The viruses SD10 and SD11 are point mutants of the Prague-C strain of Rous sarcoma virus that encode non-myristylated p60v-src. They do not induce the transformation of chicken fibroblasts. Approximately thirty bands were detected by antibodies to phosphotyrosine in fibroblasts transformed by wild-type Prague-RSV-C, only four of which were not substrates nonmyristylated mutant p60v-src. This suggests that the phosphorylation of a large subset of the substrates of p60v-src is not sufficient for transformation.

Animals↗
PubMed2000

High-Resolution Fourier Transform Spectra of HDSe: The Interacting States (v(1) v(2) v(3))/(v(1) +/- 1 v(2) -/+ 2 v(3)) with 2v(1) + v(2) = 1, 2, 3, and 4.

For the first time, high-resolution Fourier transform spectra of HDSe in the region of the three polyads, nu(1)/2nu(2), nu(1) + nu(2)/3nu(2), and 2nu(1)/nu(1) + 2nu(2)/nu(2) + nu(3), have been recorded and analyzed. Combined with an earlier investigation of the nu(2) band, and including estimates for the unobserved "dark" 4nu(2) band, these levels were subjected to a "Global Fit," which makes use of relations between parameters within the different polyads. Since there are five isotopic species present in natural HD(M)Se (M = 82, 80, 78, 77, 76), altogether 34 vibration-rotation bands have been studied in the present contribution. The parameters determined by the Global Fit reproduce upper vibrational-rotational energies of all these bands with accuracies close to experimental precision. Copyright 2000 Academic Press.

Journal Article↗
PubMed1988

The factor V-activating enzyme (RVV-V) from Russell's viper venom. Identification of isoproteins RVV-V alpha, -V beta, and -V gamma and their complete amino acid sequences.

The complete amino acid sequences of two isoproteins of the factor V-activating enzyme (RVV-V) isolated from Vipera russelli (Russell's viper) venom were determined by sequencing S-pyridylethylated derivatives of the proteins and their peptide fragments generated by either chemical (cyanogen bromide and 2-(2-nitrophenylsulfenyl)-3-methyl-3-bromoindolenine) or enzymatic (trypsin, alpha-chymotrypsin, and lysyl endopeptidase) cleavages. Both enzymes, designated RVV-V alpha and RVV-V gamma, consist of 236 amino acid residues and have a N-linked oligosaccharide chain at Asn229. The six amino acid substitutions between RVV-V alpha and -V gamma are: Thr22(alpha)-Ala22(gamma), Gly29(alpha)-Ala29(gamma), Gln191(alpha)-Glu191(gamma), Ile192(alpha)-Met192(gamma), Gln193(alpha)-His193(gamma), and Asn224(alpha)-Ser224(gamma). The molecular weights were calculated as 26,182 for RVV-V alpha and 26,167 for RVV-V gamma. The sequences of the RVV-V isoproteins exhibited 62% identity with that of batroxobin, a thrombin-like enzyme present in Bothrops atrox venom, and 33% identity with that of human thrombin B chain. The most interesting difference between the structures of RVV-V and other trypsin-type serine proteases is that the conservative Ser214-Trp215-Gly216 sequence (chymotrypsinogen numbering), considered as the site of antiparallel beta-sheet formation between the protein substrate and most serine proteases, has been replaced by the corresponding sequence Ala-Gly-Gly.

Amino Acid Sequence↗
PubMed1997

Myelin basic protein-specific and TCR V beta 8.2-specific T-cell lines from TCR V beta 8.2 transgenic mice utilize the same V alpha and V beta genes: specificity associated with the V alpha CDR3-J alpha region.

Our analysis of TCR V gene usage in mice transgenic for the V beta 8.2 gene has demonstrated that T cells isolated from the spinal cord of these transgenic mice during active experimental autoimmune encephalomyelitis were significantly biased for V alpha 2 expression. This V alpha 2 bias was noted in T cells derived from the periphery as well but only after stimulation with specific antigen. Thus, spinal cord-derived pathogenic T cells had already undergone activation and expansion within the central nervous system environment of these mice. As part of an investigation of regulatory function in these V beta 8.2 transgenic mice, two T cell lines were selected. The first T cell line is encephalitogenic and specific for the dominant myelin basic protein peptide NAc1-11, while the second T cell line is specific for the V beta 8.2 protein. Surprisingly, polymerase chain reaction and sequence analysis of the TCR from both the T cell lines demonstrated that they utilize identical V beta, D beta, J beta, and V alpha gene segments. The only difference found was in their use of the J alpha gene segment, indicating that this region of the TCR molecule can play a key role in determining antigen specificity.

Animals↗
PubMed1999

H(3)Si(37)Cl Revisited with High Resolution: The Ground State and the v(2) = 1; v(3) = 1, 2, and 3; v(5) = 1; v(6) = 1 and 2; and v(3) = v(6) = 1 States.

The infrared spectrum in the range 400-1600 cm(-1) of isotopically pure H(3)Si(37)Cl has been recorded at high resolution (2.4-6.6 x 10(-3) cm(-1)) and analyzed. Fifteen bands have been studied, namely the four fundamentals nu(3) (543.968 cm(-1)), nu(6) (663.738 cm(-1)), nu(2) (947.982 cm(-1)), and nu(5) (950.657 cm(-1)), the overtone bands 2nu(3), 2nu(0)(6), and 2nu(-/+2)(6), the combination band nu(3) + nu(6), and seven hot bands. Improved ground state constant parameters have been obtained, including all four sextic distortion constants. As for the J-independent parameters A(0), D(0)(K), and H(0)(K), they were determined mainly through the "loop method" involving nu(6), 2nu(-/+2)(6), and 2nu(-/+2)(6)-nu(+/-1)(6) and checked through the strong interactions between nu(2) and nu(5), producing some "forbidden lines." The nu(2)/nu(5) dyad was fitted with success using two different reduced Hamiltonians. Concerning nu(3) and nu(6), in spite of their relatively large separation, a Coriolis interaction could be evidenced. In both nu(2)/nu(5) and nu(3)/nu(6) interacting systems the sign of the interaction was found positive. As for the overtones, 2nu(3) was treated as isolated and 2nu(0)(6) and 2nu(-/+2)(6) as linked together by an l(2, 2) interaction. The data on the v(3) = v(6) = 1 levels were obtained mainly from the two hot bands nu(3) + nu(6) - nu(3) and nu(3) + nu(6) - nu(6), and marginally from the weak band nu(3) + nu(6), and also fitted as for an isolated level. A weak x,y-Coriolis interaction with level crossing between K/(kl - 1) = 21 and 22, and a local l(1, -2) resonance at K = 13/kl = -15 between 2nu(3) and nu(5) were furthermore detected. Copyright 1999 Academic Press.

Journal Article↗
PubMed1984

Human placenta type V collagens. Evidence for the existence of an alpha 1(V) alpha 2(V) alpha 3(V) collagen molecule.

Human type V collagen was purified from placenta and found to contain alpha 1(V), alpha 2(V), and alpha 3(V) chains in varying ratios. Using any of three independent nondenaturing methods (phosphocellulose chromatography, high-performance ion-exchange chromatography on IEX-540 DEAE, and ammonium sulfate precipitation), this preparation could be resolved into two fractions. Analysis of the two fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that one fraction contained alpha 1(V) and alpha 2(V) in a 2:1 ratio and the other contained alpha 1(V), alpha 2(V), and alpha 3(V) in a 1:1:1 ratio. When the crude placental type V collagen was electrophoresed under nondenaturing conditions, two bands were observed, one co-migrating with purified (alpha 1(V]2 alpha 2(V) and the other co-migrating with the fractions containing alpha 1(V), alpha 2(V), and alpha 3(V) chains in a 1:1:1 ratio. Electrophoresis in a second dimension under denaturing conditions confirmed that the fast-migrating band contained (alpha 1(V]2 alpha 2(V) and that the slow-migrating band contained the three chains in equimolar ratio. CD spectra of the two fractions and resistance to trypsin-chymotrypsin digestion confirmed that the two fractions contain triple helical collagen. Thermal denaturations were monitored by the changes in CD signal at 221 nm. The two fractions purified by ammonium sulfate precipitation melted at 39.1 and 36.4 degrees C for the (alpha 1(V]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V) fractions, respectively. Trypsin cleavage of these two native fractions at temperatures near melting produced completely different fragmentation patterns, indicating different partial unwinding sites of the alpha 1(V) and alpha 2(V) chains in the two preparations and thus different molecular assemblies. Our data demonstrate the existence of two different molecular assemblies of type V collagen in human placenta consisting of (alpha 1(V]2 alpha 2(V) and alpha 1(V) alpha 2(V) alpha 3(V) heterotrimers.

Acetates↗
PubMed1990

Stimulation of all T cells bearing V beta 1, V beta 3, V beta 11 and V beta 12 by staphylococcal enterotoxin A.

To determine the molecular mechanisms of T cell stimulation by staphylococcal enterotoxin A (SEA), we examined the expression of T cell receptor (TcR) V beta on the T cells from four strains of mice stimulated in vitro with SEA, using flow cytometric analysis for the number of T cells bearing V beta 3, V beta 6, V beta 8, V beta 11 and RNA blotting analysis for the amount of transcripts of V beta 1, V beta 5 and V beta 12. The number of T cell blasts bearing V beta 1, V beta 3, V beta 1 or V beta 12 were increased in the T cell blasts proliferating in vitro in response to SEA in C57BL/6 mice. In AKR/J mice, which contain few V beta 11- or V beta 12-bearing T cells due to a tolerance to the self-MHC class II IE-antigens, T cells bearing V beta 1 or V beta 3 responded to SEA. SEA enriched only V beta 1-bearing T cells in BALB/c mice carrying Mls-2a which lack Mls-1a-reactive V beta 3-bearing T cells as well as V beta 11- and V beta 12-bearing T cells. In spite of the presence of V beta 1-bearing T cells, C3H/He T cells exhibited a very low responsiveness to SEA. T cell repertoires skewed by clonal deletion of self-reactive T cells may in part account for the different sensitivity to SEA among the different strains. A tolerance to SEA can be established in C57BL/6 mice which have been primed i.v. with SEA and treated i.p. with 200 mg/kg of cyclophosphamide 2 days later. All mature T cells bearing V beta 3 or V beta 11 were virtually abolished in the periphery of tolerant mice. These results suggest that most T cells reactive to SEA bear V beta 1, V beta 3, V beta 11 or V beta 12 and that clonal deletion of mature T cells reactive to SEA may account for the cellular mechanisms for cyclophosphamide-induced tolerance to SEA.

Animals↗
PubMed1991

Characterization of a new minor lymphocyte stimulatory system. I. Cluster of self antigens recognized by "I-E-reactive" V beta s, V beta 5, V beta 11, and V beta 12 T cell receptors for antigen.

In the mouse, two sets of V beta gene products have been shown to be associated with T cell recognition of endogenous self Ag. One of these is the set of V beta associated with T cell reactivities to stimulatory Mls gene products, Mlsa (V beta 6, V beta 8.1, V beta 9) or Mlsc (V beta 3); another is the set of V beta, such as V beta 5, V beta 11, V beta 12, or V beta 17a, which were originally found to be related to I-E recognition. Although the Mls system has been well characterized, little is known about the nature of the ligands for the second set of V beta. In this work, we describe the evidence that the natural ligand or ligands of V beta 5, V beta 11, and V beta 12 may be novel Mls determinants that are recognized by naive T cells at a high precursor frequency and function as the ligand for clonal deletion of self-reactive T cells by negative selection. However, surprisingly, unlike the conventional Mls system, in which all V beta associated with Mlsa recognition or Mlsc recognition are uniformly deleted in those animals expressing the relevant Mls type, expression of these three V beta segregates independently among strains. Based on these observations, the nature of T cell recognition for this new Mls gene product(s) is discussed.

Animals↗