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171.
Bernard N. Violand Michael R. Schlittler Kevin L. Duffin Christine E. Smith 《Journal of Protein Chemistry》1995,14(5):341-347
The disulfide bond assignments of human alanyl tissue factor pathway inhibitor purified fromEscherichia coli have been determined. This inhibitor of the extrinsic blood coagulation pathway possesses three Kunitz-type inhibitor domains, each containing three disulfide bonds. The disulfide bond pairings in domains 1 and 3 were determined by amino acid sequencing and mass spectrometry of peptides derived from a thermolysin digest. However, thermolysin digestion did not cleave any peptide bonds within domain 2. The disulfide bond pairings in domain 2 were determined by isolating it from the thermolysin treatment and subsequently cleaving it with pepsin and trypsin into peptides which yielded the three disulfide bond pairings in this domain. These results demonstrate that the disulfide pairings in each of the three domains of human tissue factor pathway inhibitor purified fromEscherichia coli are homologous to each other and also to those in bovine pancreatic trypsin inhibitor. 相似文献
172.
Fabrice Cornille Loïc Martin Christine Lenoir Didier Cussac Bernard P. Roques Marie-Claude Fournié-Zaluski 《Letters in Peptide Science》1997,4(4-6):207-212
The light chain of tetanus neurotoxin (TeNT L chain)has been shown to be endowed with zinc endopeptidaseactivity, selectively directed towards theGln76–Phe77 bond of synaptobrevin, avesicle-associated membrane protein criticallyinvolved in neuroexocytosis. In previous reports,truncations at the NH2- and COOH-terminus ofsynaptobrevin have shown that the sequence 39–88 ofsynaptobrevin is the minimum substrate of TeNT,suggesting either the requirement of a well-definedthree-dimensional structure of synaptobrevin or a rolein the mechanism of substrate hydrolysis for residuesdistal from the cleavage site. In this study, theaddition of NH2- and COOH-terminal peptides ofsynaptobrevin, S 27–55 (S1) and S 82–93(S2), to the synaptobrevin fragment S 56–81allowed the cleavage of this latter peptide by TeNT tooccur. This appears to result from an activationprocess mediated by the simultaneous binding ofS1 and S2 with complementary sites presenton TeNT as shown by surface plasmon resonanceexperiments. All these results favor anexosite-controlled hydrolysis of synaptobrevin by TeNTprobably involving a conformational change of thetoxin. This could account for the high degree ofsubstrate specificity of TeNT and, probably, botulinumneurotoxins. 相似文献
173.
Sabine Castano Bernard Desbat Isabelle Cornut Philippe Méléard Jean Dufourcq 《Letters in Peptide Science》1997,4(4-6):195-200
De novo designed extremely simplified amphipathic basicLeuiLysj (i = 2j) peptides of 8, 9 and 15residues were synthesized to clarify the mechanism of action of naturalcytotoxic and hemolytic small proteins or peptides. They proved to havestrong hemolytic activity towards human erythrocytes which increases withpeptide length. These peptides are highly surface active and form stablepeptidic films at the air/water interface. The sensitive and efficient FTIRmodulated polarization technique (PMIRRAS) allows one to obtain in situstructural and orientational information about the peptides at theinterface. A transition of secondary structure is observed: the shorterpeptides (8 and 9 residues) adopt -sheet structures while the longerone (15 residues) is folded into an -helix. In both cases, the peptideslie with the axis parallel to the interface. Their insertion into adimyristoylphosphatidylcholine monolayer can be followed from the increasein the surface and/or pressure of the films. In the mixed films, thepeptides adopt the same structure and orientation as observed at theair/water interface. Therefore, among the same series of peptides, atransition from -sheet to -helix occurs when the length increases(roughly >10 aa), but despite this drastic change both types ofstructures result in strongly hemolytic peptides. 相似文献
174.
Joël Chopineau Stéphane Robert Laurence Fenart Roméo Cecchelli Bernard Lagoutte Stéphanie Paitier Marie-Pierre Dehouck Dominique Domurado 《Letters in Peptide Science》1997,4(4-6):313-321
Acylated proteins play a crucial role in cellphysiology because of their increased interaction withmembranes. Their isolation is difficult as aconsequence of their low cellular concentration andtheir chemical preparation is problematic due tosolubility problems. Through the use of reversedmicelles, we produced tens of milligrams of acylatedribonucleases A, chosen as a model, purified them bysemi-preparative high performance liquidchromatography (HPLC) and characterized them by analyticalHPLC, capillary electrophoresis, mass spectrometry, peptide mapping, Edman degradation and enzyme activity. We nextscrutinized the interaction with an in vitro blood–brainbarrier model and demonstrated that palmitoylated andstearoylated ribonucleases A are transported from onecompartment to the other across the cellular monolayer,in contrast to the native enzyme. 相似文献
175.
Christelle David Laurent Bischoff Hervé Meudal Catherine Llorens-Cortes Bernard Pierre Roques Marie-Claude Fournié-Zaluski 《Letters in Peptide Science》1997,4(4-6):411-414
In order to study the physiological role of aminopeptidase A (APA),several -mercapto--amino acyl dipeptides were synthesized toobtain compounds having a high affinity for APA and a high selectivityversus aminopeptidase N (APN). Sulfonamide and carboxylate moieties whichhave been shown to be recognized by the S1 subsite of theenzyme were introduced on the side chain of the -mercapto--aminoacyl sub-unit, the latter being coupled to dipeptides optimized to interactwith the S1 andS2 subsites by means of combinatorialchemistry. Good affinities (16 nM) were obtained, the selectivity factorsbeing up to 160-fold versus APN. 相似文献
176.
R. L. Wolff Bernard Comps Anne M. Marpeau Laurent G. Deluc 《Trees - Structure and Function》1997,12(2):113-118
The fatty acid compositions of the seed oils from ten pine species have been established by capillary gas-liquid chromatography
of the methyl esters. With regard to either normal fatty acids or Δ5-olefinic acids, the general pattern of fatty acids did
not differ from that of other pine seed oils reported previously. The main fatty acid was linoleic (9,12–18:2) acid (44.4–57.1%),
followed by either oleic (9–18:1) acid (13.4–24.5%) or pinolenic (5,9,12–18:3) acid (1.5–25.2%). When applying multivariate
analyses to the chemometric data (13 variables) of 49 pine species (ca. 40% of the living pine species), it was possible to
distinguish between several sections: Pinea, Longifolia, Halepensis, Ponderosa-Banksiana, Sylvestris, and Cembra. The latter section was clearly divided into two sub-groups. A few species that presented a low overall content of Δ5-olefinic
acids, and that grow in warm-temperate regions, were isolated from the bulk of other pine species. It is hypothesized that
Δ5-olefinic acids might be related to cold-acclimation.
Received: 5 June 1997 / Accepted: 17 August 1997 相似文献
177.
The Arabidopsis MALE STERILITY 2 protein shares similarity with reductases in elongation/condensation complexes 总被引:16,自引:0,他引:16
Mark G.M. Aarts Rachel Hodge Kriton Kalantidis Dion Florack Zoe A. Wilson Bernard J. Mulligan Willem J. Stiekema Rod Scott y Pereira 《The Plant journal : for cell and molecular biology》1997,12(3):615-623
The Arabidopsis thaliana MALE STERILITY 2 ( MS2 ) gene product is involved in male gametogenesis. The first abnormalities in pollen development of ms2 mutants are seen at the stage in microsporogenesis when microspores are released from tetrads. Expression of the MS2 gene is observed in tapetum of wild-type flowers at, and shortly after, the release of microspores from tetrads. The MS2 promoter controls GUS expression at a comparable stage in the tapetum of transgenic tobacco containing an MS2 promoter–GUS fusion. The occasional pollen grains produced by mutant ms2 plants have very thin pollen walls. They are also sensitive to acetolysis treatment, which is a test for the presence of an exine layer. The MS2 gene product shows sequence similarity to a jojoba protein that converts wax fatty acids to fatty alcohols. A possible function of the MS2 protein as a fatty acyl reductase in the formation of pollen wall substances is discussed. 相似文献
178.
The available amino acid sequences of the α-amylase family (glycosyl hydrolase family 13) were searched to identify their
domain B, a distinct domain that protrudes from the regular catalytic (β/α)8-barrel between the strand β3 and the helix α3. The isolated domain B sequences were inspected visually and also analyzed
by Hydrophobic Cluster Analysis (HCA) to find common features. Sequence analyses and inspection of the few available three-dimensional
structures suggest that the secondary structure of domain B varies with the enzyme specificity. Domain B in these different
forms, however, may still have evolved from a common ancestor. The largest number of different specificities was found in
the group with structural similarity to domain B from Bacillus cereus oligo-1,6-glucosidase that contains an α-helix succeeded by a three-stranded antiparallel β-sheet. These enzymes are α-glucosidase,
cyclomaltodextrinase, dextran glucosidase, trehalose-6-phosphate hydrolase, neopullulanase, and a few α-amylases. Domain B
of this type was observed also in some mammalian proteins involved in the transport of amino acids. These proteins show remarkable
similarity with (β/α)8-barrel elements throughout the entire sequence of enzymes from the oligo-1,6-glucosidase group. The transport proteins, in
turn, resemble the animal 4F2 heavy-chain cell surface antigens, for which the sequences either lack domain B or contain only
parts thereof. The similarities are compiled to indicate a possible route of domain evolution in the α-amylase family.
Received: 4 December 1996 / Accepted: 13 March 1997 相似文献
179.
180.
Bernard T. Barcio S. Ramaswamy K. Suzanne Barber 《Flexible Services and Manufacturing Journal》1997,9(1):51-80
An environment to support the modeling, analysis, simulation, and development of state transition models, SMOOCHES (State Machines for Object-Oriented Concurrent Hierarchical Engineering Specifications), is presented. SMOOCHES allows the hierarchical construction, analysis, and simulation of state transition models in an object-oriented distributed environment. Statecharts (see Harel 1987b), a powerful mechanism for state transition specification, are fundamental to the development of SMOOCHES. To assist in the specification of hierarchical state transition models for distributed and reactive systems, statecharts are extended by introducing the concept of exit-safe states. SMOOCHES allows the specification of objects in the system with hierarchical state transition models and the derivation of new classes of objects through inheritance. A graphical monitoring system has been developed to represent and simulate the object state life cycles and monitor event generations. The example presented illustrates the modeling and simulation of different state life cycles of an assembly robot. 相似文献