摘要:

AbstractThe complexes Cu(OBt)2and Cu(OAt)2, which are derived from copper(II) and HOBt and HOAt, respectively, are shown to be more effective in suppressing racemization during solid‐phase peptide synthesis (SPPS) than are those compounds currently being used for this purpose. These compounds can readily be used in conjunction with the commonly applied coupling reagents in fully automated systems for solid‐phase peptide chemistry. Copyright © 2001 European Peptide Society and John Wiley&Sons,

ISSN:1075-2617    

DOI:10.1002/psc.299

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThe possible influence of thermal motion on1H chemical shifts is discussed for a small stable protein, the bovine pancreatic Kunitz trypsin inhibitor (BPTI). The thermal effects on the aromatic side chains and on the backbone are treated separately. The thermal motion of the aromatic side chains is accounted for in terms of their rotation around the CαCβbond and the motion of each individual proton is interpreted as a ratio between the amount of ordered and quite disordered states. The influence of hydrogen bonds is introduced as an extra contribution to the chemical shifts of the bonded proton. Their contribution to the chemical shifts resulting from the polarization of the peptide bond is investigated, as is their influence on local flexibility. Finally, the relative importance of each contribution to the chemical shift information is compared. Copyright © 2001 European Peptide Society and John Wiley&Sons,

ISSN:1075-2617    

DOI:10.1002/psc.300

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractSix novel cyclic enkephalin analogues have been synthesized. Cyclization of the linear peptides containing basic amino acid residues in position 2 and 5 was achieved by treatment with bis(4‐nitrophenyl)carbonate. It was found that some of the compounds exibit unusually highµ‐opioid activity in the guinea pig ileum (GPI) assay. The 18‐membered analogue cyclo(Nε,Nβ′‐carbonyl‐

ISSN:1075-2617    

DOI:10.1002/psc.303

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThree dehydrotetrapeptides of rationally varying structure were prepared and tested as affectors of cathepsin C. These compounds appeared to be substrates of the enzyme, being equipotent with their classical counterparts. Thus, replacement of amino acid in a short peptide by corresponding dehydroamino acid does not prevent cathepsin C in recognizing dehydropeptide as its substrate. Copyright © 2001 European Peptide Society and John Wiley&Sons, Ltd

ISSN:1075-2617    

DOI:10.1002/psc.307

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractAn experimental system is described, permitting a detailed and systematic analysis of the factors governing self‐assembly of amphipathic helices, e.g. to a four‐helical bundle, a subject of major relevance for tertiary structure formation, protein folding and design. Following the Template Assembled Synthetic Proteins (TASP) approach, helices of different packing potential are competitively assembled in solution with a preformed two‐helix TASP molecule, and after equilibration are covalently attached (‘template trapping’) via chemoselective thioether formation. The quantitative analysis of the individual TASP molecules by high performance liquid chromatography (HPLC) and electrospray mass spectrometry (ES‐MS) allows the delineation of the role of complementary packing in helix bundle formation. The procedure established represents a general tool for the experimental verification of modern concepts in molecular recognition. Copyright © 2001 European Peptide Society and John Wil

ISSN:1075-2617    

DOI:10.1002/psc.308

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractThis paper presents a new protecting group, the (2‐nitrofluoren‐9‐yl)methoxycarbonyl group. Investigations on the properties of this new modification of the Fmoc‐system, such as the solvent‐dependant photochemical cleavage, and enhanced lability towards bases, are described, as well as UV‐kinetic measurements of the cleavage reaction. In addition, the incorporation of the (2‐nitrofluoren‐9‐yl)methoxycarbonyl group into two peptides, and a sequence‐dependant photochemical cleavage reaction are reported. Copyright © 2001 European Peptide Society and

ISSN:1075-2617    

DOI:10.1002/psc.309

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractBackbone modifications have been introduced into the melanoma derived peptide MART‐1(27‐35)to increase its binding to class I major histocompatibility complex HLA‐A2 molecule, and ultimately to enhance its immunogenicity. Each analogue was obtained by replacing one peptide bond at a time in the natural epitope by the aminomethylene (CH2‐NH) surrogate. All analogues displayed an increased resistance to proteolysis. Interestingly, the comparative results showed that five analogues bound more efficiently to HLA‐A2 than the parent peptide. On the other hand, two pseudopeptide/HLA‐A2 complexes were recognized by one melanoma‐specific T cell clone. Close examination of the impact of such modifications at the molecular level provides useful supports for the rational design of stable compounds with applications in anti‐tumour specific immunotherapy and in vaccine development. Copyright © 2001 European Peptide Society and John

ISSN:1075-2617    

DOI:10.1002/psc.311

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY

摘要:

AbstractTwo analogues of the 29 amino acid sequence of human growth hormone‐releasing hormone, namely [Nle27]hGH‐RH(1‐29)‐NH2and [Orn12,21,Nle27]hGH‐RH(1‐29)‐NH2, have been synthesized and subjected to digestion by trypsin. The course of degradation was followed using RP‐HPLC and ESI‐MS. Several intermediates and final products of degradation were identified and conclusions regarding the rate of cleavages at different positions occupied by Lys and Arg residues were drawn. The analogue containing ornithine was found to be less susceptible to hydrolysis by trypsin: the 12‐13 and 21‐22 peptide bonds were completely resistant to the cleavage. The results show that by replacing Lys with Orn, a possibility exists to design new peptides, which could be more stable in biological fluids. Copyright © 2001 European Peptide Society an

ISSN:1075-2617    

DOI:10.1002/psc.316

出版商:John Wiley&Sons, Ltd.    

年代:2001

数据来源: WILEY