摘要:

AbstractInsects are amazingly resistant to bacterial infections. To combat pathogens, insects rely on cellular and humoral mechanisms, innate immunity being dominant in the latter category. Upon detection of bacteria, a complex genetic cascade is activated, which ultimately results in the synthesis of a battery of antibacterial peptides and their release into the haemolymph. The peptides are usually basic in character and are composed of 20–40 amino acid residues, although some smaller proteins are also included in the antimicrobial repertoire. While the proline‐rich peptides and the glycine‐rich peptides are predominantly active against Gram‐negative strains, the defensins selectively kill Gram‐positive bacteria and the cecropins are active against both types. The insect antibacterial peptides are very potent: their IC50(50% of the bacterial growth inhibition) hovers in the submicromolar or low micromolar range. The majority of the peptides act through disintegrating the bacterial membrane or interfering with membrane assembly, with the exception of drosocin, apidaecin and pyrrhocoricin which appear to deactivate a bacterial protein in a stereospecific manner. In accordance with their biological function, the membrane‐active peptides form ordered structures, e.g. α‐helices or β‐pleated sheets and often cast permeable ion‐pores. Their cytotoxic properties were exploited in in vivo studies targeting tumour progression. Although the native peptides degrade quickly in biological fluids other than insect haemolymph, structural modifications render the peptides resistant against proteases without sacrificing biological activity. Indeed, a pyrrhocoricin analogue shows lack of toxicity in vitro and in vivo and protects mice against experimentalEscherichia coliinfection. Careful selection of lead molecules based on the insect antibacterial peptides may extend their utility and produce viable alternatives to the conventional antimicrobial compounds for mammalian therapy. Copyright © 2000 European Peptide Society and

ISSN:1075-2617    

DOI:10.1002/1099-1387(200010)6:10<497::AID-PSC277>3.0.CO;2-W

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractSynthesis of chemokines via stepwise SPPS approaches has been shown to be a challenge. Herein, a complete study of different coupling methods, solvents and temperature combined with a continuous‐flow synthesizer equipped with feedback monitoring was carried out. The results from this study indicate that this family of molecules can be prepared using an Fmoc/Butchemical approach and provide a general method to apply for the elongation of other difficult sequences. Copyright © 2000 European Peptide Society and John Wiley&Sons, L

ISSN:1075-2617    

DOI:10.1002/1099-1387(200010)6:10<512::AID-PSC269>3.0.CO;2-A

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractPseudokonins KL III and KL VI are two natural ten‐residue peptides, which both contain the (Xaa‐Yaa‐Aib‐Pro) motif and exhibit an unusual C‐terminus. They have been isolated from the fungus Trichoderma pseudokoningii by intensive reversed‐phase HPLC, beside peptaibols classically C‐ended by a β‐amino alcohol. The amino acid sequences and the chemical structures of the C‐ends have been determined by the combined use of positive ion LSI‐MS and two‐dimensional homo‐ and heteronuclear NMR, including COSY, TOCSY, ROESY,13C heteronuclear single quantum correlation (HSQC) and heteronuclear multiple bond correlation (HMBC). Instead of one of the amino alcohols usually found as C‐terminal residue in peptaibols, pseudokonins KL III and KL VI are characterized by ‐Pro‐NH2and cyclo‐(Aib‐

ISSN:1075-2617    

DOI:10.1002/1099-1387(200010)6:10<519::AID-PSC273>3.0.CO;2-6

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

摘要:

AbstractA replacement of the acetic acid moiety by valeric acid within the 4‐hydroxymethylphenoxyacetic acid (HMP) linker (Sheppard RC, Williams BJ. Acid‐labile resin linkage agents for use in solid phase peptide synthesis. Int. J. Peptide Protein Res. 1982; 20: 451–454) significantly improved its performance in terms of loading capacity, yield and purity of the final products. The results indicated the spacer–linker combination and type of solid supports are important factors for solid‐phase synthesis. Copyright © 2000 European Peptide Society and John Wiley

ISSN:1075-2617    

DOI:10.1002/1099-1387(200010)6:10<534::AID-PSC288>3.0.CO;2-3

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY

ISSN:1075-2617    

DOI:10.1002/1099-1387(200010)6:10<539::AID-PSC301>3.0.CO;2-E

出版商:John Wiley&Sons, Ltd.    

年代:2000

数据来源: WILEY