摘要:

AbstractA series of terminally blocked peptides (to the pentamer level) froml‐Ala and the cyclic Cα,α‐disubstituted Gly residue Afc and one Gly/Afc dipeptide have been synthesized by solution method and fully characterized. The molecular structure of the amino acid derivative Boc‐Afc‐OMe and the dipeptide Boc‐Afc‐Gly‐OMe were determined in the crystal state by X‐ray diffraction. In addition, the preferred conformation of all of the model peptides was assessed in deuterochloroform solution by FT‐IR absorption and1H‐NMR. The experimental data favour the conclusion that the Afc residue tends to adopt either the fully‐extended (C5) or a folded/helical structure. In particular, the former conformation is highly populated in solution and is also that found in the crystal state in the two compounds investigated. A comparison with the structural propensities of the strictly related Cα,α‐disubstituted Gly residues Ac5c and Dϕg is made and the implications for the use of the Afc residue in conformationally constrained analogues of bioactive peptides are briefly examined. A spectroscopic (UV absorption, fluorescence, CD) characterization of this novel aromatic Cα,α‐disubstituted Gly residue is also reported. Copyright © 1999 European Peptide

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199902)5:2<61::AID-PSC173>3.0.CO;2-4

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractA new type of microtiter plate capable of binding biomolecules covalently in a one step procedure was used to map linear B‐cell epitopes in two different proteins using a peptide‐based solid phase immunoassay. The method was compared with a conventional immobilization method using passive adsorption to microtiter plates. An array of 15‐mer peptides, overlapping by five amino acids, representing the entire sequences of ubiquitin and murine tumor necrosis factor‐α, respectively, was synthesized. The peptides were immobilized covalently using the new, specialized microtiter plates or non‐covalently using conventional ELISA microtiter plates of the high binder type. Subsequently, specific antisera to ubiquitin or murine tumor necrosis factor‐α were added to identify potential linear B‐cell epitopes. All peptides, which were recognized on the conventional microtiter plates, were also recognized on the plates with the covalently bound peptides. In addition, the covalent immobilization method revealed epitopes that were not identified using the method for non‐covalent binding although the peptides were in fact present on the non‐covalent binding surface. The interaction with the hydrophobic surface of the conventional microtiter plate apparently interfered negatively with antibody recognition. The covalently binding microtiter plates described here could be useful for identification of new B‐cell epitopes in protein antigens. Copyright © 1999 European Peptide Society an

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199902)5:2<75::AID-PSC175>3.0.CO;2-M

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractThe structures of two synthetic peptides with sequences corresponding to the C‐terminal region of the naturally occurring 14‐residue peptaibol trichovirin have been determined. The crystal structures of 8‐ and 12‐residue segments are presented and are compared with the structures of the tetrapeptide and of the 9‐residue segment, which have been reported earlier. A comparison between these segments leads to the hypothesis that the three‐dimensional structure of trichovirin is to a large extent determined by the properties of a periodically repeating ‐Aib‐Pro‐ pattern in the sequence of the peptide. Copyright © 1999 European Peptide Society and Jo

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199902)5:2<83::AID-PSC174>3.0.CO;2-U

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractTrikoningin KB II, a ten‐amino acid residue lipopeptaibol blocked at the N‐terminus by then‐octanoyl group and at the C‐terminus by the 1,2‐amino alcoholl‐leucinol, and extracted from the fungusTrichoderma koningii, exhibits membrane‐modifying properties. We have synthesized by solution‐phase methods trikoningin KB II and several analogues with acyl chains of different length at the N‐ and C‐termini. Permeability measurements showed that an appropriate length of the linear acyl chain is a more important characteristic for the onset of significant membrane‐modifying activity than its position in the peptide chain. Copyright © 1999 European Peptide Society an

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199902)5:2<96::AID-PSC185>3.0.CO;2-G

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY

摘要:

AbstractSynthetic collagen peptides containing larger numbers of Gly‐Pro‐Hyp repeats are difficult to purify by standard chromatographic procedures. Therefore, efficient strategies are required for the synthesis of higher molecular weight collagen‐type peptides. Applying the Fmoc/tBu chemistry, a comparative analysis of the standard stepwise chain elongation procedure on solid support with the procedure based on the use of the synthons Fmoc‐Gly‐Pro‐Hyp(tBu)‐OH and Fmoc‐Pro‐Hyp‐Gly‐OH was performed. The crude products resulting from the stepwise elongation procedure and from the use of Fmoc‐Gly‐Pro‐Hyp(tBu)‐OH clearly revealed large amounts of microheterogeneities that result from incomplete imino acid acylation as well as from diketopiperazine formation with cleavage of Gly‐Pro units from the growing peptide chain. Conversely, by the use of the Fmoc‐Pro‐Hyp‐Gly‐OH synthon, the quality of the crude products was significantly improved; moreover, protection of the Hyp side chain hydroxyl function is not required using the Fmoc/tBu strategy. With this optimized synthetic procedure, relatively large collagen‐type peptides were obtained in satisfactory yields as highly homogeneous compounds. Copyright © 1999 Europea

ISSN:1075-2617    

DOI:10.1002/(SICI)1099-1387(199902)5:2<103::AID-PSC188>3.0.CO;2-N

出版商:John Wiley&Sons, Ltd.    

年代:1999

数据来源: WILEY