摘要:

AbstractWe synthesized one V3 peptide each from HTLV‐IIIB, Thai A and Thai B, conjugating then to the T cell epitope of theenvregion, and we also synthesized a p17 protein peptide of thegagregion (HGP‐30). These peptide were then coupled to 8‐lysine copolymers usingN‐succinimidyl maleimido carboxylate (Mr= ca 60 000). We designated this the branched lysine oligopeptide method. The large peptide complexes constructed from these four macromolecular peptide were used with aluminium hydroxide or complete Freund's adjuvant to immunize mice and rabbits four times. ELISA assay with aluminium hydroxide or complete Freund's adjuvant to immunize mice and rabbits four times. ELISA assay showed high titres of anti‐peptide antibodies to each V3loop peptide and the HGP‐30 peptide. Strong inhibition of CD4+dependent cell fusion was obtained with these antisera when IIIb, Thai A and Thai B strains of human immunodeficiency virus (HIV) were used. Strong anti‐fusion inhibition was also observed with two other HIV strains. In addition, an increase of the anti‐HIV effect was observed when we used sera obtained by multicomponent vaccine immunization. The same kind of inhibition was also observed in p24 assay systems using these immunized antisera. Activation of IL‐2 production in lymphocytes was observed in p24 assay systems using these immunized antisera. Activation of IL‐2 production in lymphocytes was observed in mice immunized with this vaccine. These results suggest that immunization with macromolecular peptide complexes can result in strong immunogen

ISSN:0952-3499    

DOI:10.1002/jmr.300060302

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractA Computer program is presented that models the binding of selected chemical groups to a protein surface. The groups are successively incorporated at energetically favourable positions to build up a pharmacophore pattern that may be used as the basis for a database search for possible ligands. The ability to predict known binding points in a trypsin–inhibitor complex is demonstrated, and the results from a run on dihydrofolate reductase are shown to be usable as a pharmacophore pattern for a database searc

ISSN:0952-3499    

DOI:10.1002/jmr.300060303

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe binding of phosphorylase kinase to calmodulin‐Sepharose 4B was studied by column and batch methods. It was found that the Ca2+dependence of the interaction strongly depended strongly depended on the degree of substitution of agarose with calmodulin. Equilibrium adsorption isotherms (i.e., bulk ligand binding functions and lattice site binding functions) of phosphorylase kinase were measured on calmodulin‐Sepharose. Sigmoidal bulk ligand binding functions (bulk adsorption coefficients: 1.5–5.8) were found which indicate intermolecular attraction during binding. Hyperbolic lattice site binding functions (lattice adsorption coefficients: 1.0) were obtained thus excluding the existence of a critical surface concentration of immobilized calmodulin and indicating single independent binding sites on the gel surface and on phosphorylase kinase. These findings were combined to optimize the adsorption of phosphorylase kinase on calmodulin‐Sepharose, for purification procedures at low Ca2+concentrations (5–10 μM) minimizing proteolysis by calpains. With this novel method phosphorylase kinase from rabbit and frog skeletal muscle could be purified ca 100‐ and 200‐fold, respectively

ISSN:0952-3499    

DOI:10.1002/jmr.300060304

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe computer program LUDI for automated structure‐based drug design is described. The program constructs possible new ligands for a given protein of known three‐dimensional structure. This novel approach is based upon rules about energetically favourable non‐bonded contact geometries between functional groups of the protein and the ligand which are derived from a statistical analysis of crystal packings of organic molecules. In a first step small fragments are docked into the protein binding site in such a way that hydrogen bonds and ionic interactions can be formed with the protein and hydrophobic pockets are filled with lipophilic groups of the ligands. The program can then append further fragments onto a previously positioned fragments or onto an already existing ligand (e.g., a lead structure that one seeks to improve). It is also possible to link several fragments together by bridge fragments to form a complete molecule. All putative ligands retrieved or constructed by LUDI are scored. We use a simple scoring function that was fitted to experimentally determined binding constants of protein–ligand complexes. LUCI is a very fast program with typical execution times of 1–5 min on a work station and is therefore suitable for interact

ISSN:0952-3499    

DOI:10.1002/jmr.300060305

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractEndo β‐N‐acetylglucosaminidase activities were determined based on conversion of oligosaccharides containing twoN‐acetylglucosamines to the oligosaccharides with a singleN‐acetylglucosamine at the reducing terminal and following their separation on a carbohydrate analyzer. The oligosaccharides eluted from the high performance anion exchange column in the order of fucosyl‐N,N′ ‐diacetylchitobiose,N,N′ ‐diacetylchitobiose andN‐acetylglucosamine containing reducing terminals. Using this assay, differences in cleavage specificity of the glycoproteins was determined. The commercial Endo F‐peptideN‐glycosidase/glycanyl amidase (PNGase)mixture readily leaved high mannose and complex oligosaccharides (neutral and sialyated) with common core α1–6 linked fucose found in porcine thyroglobulin including the trimannosyl‐chitobiose core structure. However, the same Endo F mixture did not cleave the non‐fucosylated complex oligosaccharides found in human transferrin and also the common core structure. Glycopeptide counterparts with and without fucose were good substrates for the endoglycosidases. These results show that the specificity of these enzymes is such that they can recognize the conformational differences between free oligosaccharides and glycopeptides with and without the common core α1–6 linked fucose. In contrast, highly purified Endo F cleaved only the high mannose type oligosaccharides and was unable to cleave ovalbumin hybrid type oligosaccharides. However, it was similar to Endo H when reduced ovalbumin oligosaccharides were used as substrates, consistent with the recently isolated Endo F subfraction F1being similar to Endo H [Trimble, R. B. and Tarentino, a. L. (1991).J. Biol. Chem.266, 1646]. Results obtained in this study suggest that the complex oligosaccharides cleaving enzymes F2and F3show high specificity towards peptide free oligosaccharides with the core α1‐6 linked fucose, unlike the glycopeptide substrates. Therefore PNGase free Endo F1, F2and F3mixtures should be useful in the functional evaluation of

ISSN:0952-3499    

DOI:10.1002/jmr.300060306

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY

ISSN:0952-3499    

DOI:10.1002/jmr.300060301

出版商:John Wiley&Sons, Ltd.    

年代:1993

数据来源: WILEY