摘要:

AbstractWe report the solid phase synthesis of four pairs of

ISSN:1075-2617    

DOI:10.1002/psc.339

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractA series of terminally blocked dipeptides containingC‐terminalN‐phosphonomethylglycine (glyphosate, an extremely effective non‐selective post‐emergence herbicide) have been synthesized by a solution method. The presence of their two conformers,cis(syn) andtrans(anti), was shown in solutions by NMR spectroscopy. Molecular structures of the peptides were also determined in the solid state by X‐ray diffraction. The attempts for the selective and total removal of the groups protecting amino, carboxylic and phosphonate functions were in many cases unsuccessful due to the formation of cyclic structures and breakage of the phosphorus‐to‐carbon bond. Copyright © 2001 European Peptide Society and John W

ISSN:1075-2617    

DOI:10.1002/psc.340

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractAn expressed peptide proved to be useful as a building block for the synthesis of a polypeptide via the thioester method. A partially protected peptide segment, for use as aC‐terminal building block, could be prepared from a recombinant protein; itsN‐terminal amino acid residue was transaminated to an α‐oxoacyl group, the side‐chain amino groups were then protected witht‐butoxycarbonyl (Boc) groups, and, finally, the α‐oxoacyl group was removed. On the other hand, anO‐phosphoserine‐containing peptide thioester was synthesized via a solid‐phase method using Boc chemistry. These building blocks were then condensed in the presence of silver ions and an active ester component. During the condensation, epimerization at the condensation site could be suppressed by the use ofN,N‐dimthylformamide (DMF) as a solvent. Using this strategy, a phosphorylated partial peptide of the p21Max protein, [Ser(PO3H2)2,11]‐p21Max(1–101), was successfully synthesized. Copyright © 2001 European Peptide Societ

ISSN:1075-2617    

DOI:10.1002/psc.341

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractPrevious studies have shown the amyloid peptides, Aβ 1‐40/42, to be exceptionally difficult to assemble by Fmoc‐solid phase peptide synthesis due to the high hydrophobicity of theC‐terminal segment and resulting on‐resin aggregation. We found that the use of the stronger and more efficient base, DBU, at a concentration of 2% in DMF forNα‐Fmoc deprotection allowed substantially improved continuous flow solid phase assembly of the model peptide Aβ 29‐40/42 fragments. This suggested that, at least for these sequences, incomplete deprotection was a greater problem than incomplete amino acid acylation. This base was then used during the synthesis of both Aβ 1‐40 and Aβ 1‐42, up to and including Ser8, from which point 20% piperidine in DMF was utilized so as to avoid potential aspartimide formation at Asp7. By this means, the deprotection efficiency through the difficultC‐terminal portion of the sequence was much improved and resulted in increased availability of terminal amino groups for acylation. This simple strategy that obviates the need for special conditions significantly improved crude peptide quality and allowed considerable facilitation of subsequent purification. Copyright © 2001 European Peptide Society a

ISSN:1075-2617    

DOI:10.1002/psc.342

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThe recently identified protein, insulin 3 (INSL3), has structural features that make it abona fidemember of the insulin superfamily. Its predicted amino acid sequence contains the classic two‐peptide chain (A‐ and B‐) structure with conserved cysteine residues that results in a disulphide bond disposition identical to that of insulin. Recently, the generation ofinsl3knockout mice has demonstrated that testicular descent is blocked due to the failure of a specific ligament, the gubernaculum, to develop. The mechanism by which INSL3 exerts its action on the gubernaculum is currently unknown. The purpose of this study was to, for the first time, synthesize rat INSL3 and test its action on organ cultures of foetal rat gubernaculum. INSL3 also contains a cassette of residues Arg‐X‐X‐X‐Arg within the B‐chain, a motif that is essential for characteristic activity of another related member of the superfamily, relaxin. Hence, the relaxin activity of rat INSL3 was also tested in two different relaxin bioassays. The primary structure of rat INSL3 was determined by deduction from its cDNA sequence and successfully prepared by solid phase peptide synthesis of the two constituent chains followed by their combination in solution. Following confirmation of its chemical integrity by a variety of analytical techniques, circular dichroism spectroscopy confirmed the presence of high β‐turn and α‐helical content, with a remarkable spectral similarity to the synthetic ovine INSL3 peptide and to synthetic rat relaxin. The synthetic rat INSL3 bound with very low affinity to rat relaxin receptors and had no activity in a relaxin bioassay. Furthermore, it did not augment or antagonize relaxin activity. The rat INSL3 did however induce growth of foetal rat gubernaculum in whole organ cultures demonstrating that INSL3 has a direct action on this structure. Copyright © 2001 European Peptide Society an

ISSN:1075-2617    

DOI:10.1002/psc.344

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThis paper presents a reevaluation of the synthesis and properties of Fmoc‐His(3‐Bum)‐OH regarding its application in SPPS with minimal racemization of histidine residues during coupling and esterification reactions. By‐product formation during the deprotection of the test peptides could be significantly reduced by scavenging the concomitantly formed HCHO, e.g. with methoxyamine. Copyright © 2001 European Peptide Society and John Wiley&S

ISSN:1075-2617    

DOI:10.1002/psc.345

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThe conjugation of synthetic peptides to carrier proteins is a widely used method for immunological studies. Different coupling agents have been described to form the conjugate with carrier proteins. In this paper, we demonstrate that the antibody response toward V3‐based synthetic MAPs derived from HIV‐1, JY1 isolate, conjugated to two different carrier proteins using eitherm‐maleimidobenzoyl‐N‐hydroxysuccinimide ester (MBS) or β‐maleimidopropionic acidN‐hydroxysuccinimide ester (MPS), or succinic anhydride (SA) show different behaviors. An excellent anti‐JY1 response without a strong response to the coupling agent is observed in the case of succinic anhydride spacer. In contrast, MBS produces total abrogation of the antibody response with a high response toward the coupling agent. Copyright © 2001 European Peptide Society and Joh

ISSN:1075-2617    

DOI:10.1002/psc.336

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY