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Titolo:
COMPARISON OF THE PHOTOCHEMICAL BEHAVIOR OF 4 DIFFERENT PHOTOACTIVATABLE PROBES
Autore:
WEBER PJA; BECKSICKINGER AG;
Indirizzi:
ETH ZURICH,DEPT PHARM,WINTERTHURERSTR 190 CH-8057 ZURICH SWITZERLAND ETH ZURICH,DEPT PHARM CH-8057 ZURICH SWITZERLAND
Titolo Testata:
The journal of peptide research
fascicolo: 5, volume: 49, anno: 1997,
pagine: 375 - 383
SICI:
1397-002X(1997)49:5<375:COTPBO>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
CROSS-LINKING; REAGENTS; SYSTEMS; BINDING;
Keywords:
CROSS-LINKING REAGENTS; PEPTIDE SYNTHESIS; PHOTOAFFINITY LABELING; THYMOPENTIN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
24
Recensione:
Indirizzi per estratti:
Citazione:
P.J.A. Weber e A.G. Becksickinger, "COMPARISON OF THE PHOTOCHEMICAL BEHAVIOR OF 4 DIFFERENT PHOTOACTIVATABLE PROBES", The journal of peptide research, 49(5), 1997, pp. 375-383

Abstract

The most commonly used photoaffinity labeling probes are compared, which are aryl azides, aryl diazirines, alpha-diazocarbonyls and benzophenone-derivatives. The compounds were used under identical conditions and crosslinking efficiency, influence of water, irradiation requirements, and by-products were investigated. Using the pentapeptide thymopentin (TP5) as a model system, we synthesized four analogues by solid-phase peptide synthesis and partially N-terminal modification to obtain[p-(3-trifluoromethyl)diazirinophenylalanine(5)] TP5, [p-benzoylphenylalanine(5)] TP5, 4-azidobenzoyl-TP5 and 2-diazo-3,3,3-trifluoropropionyl-TP5. The peptides were characterized by HPLC and ion-spray mass spectroscopy. Irradiation of the peptides with two different ultravioletsources was carried out in water, il-propanol and water/n-propanol toimitate both hydrophobic and hydrophilic peptide/protein-interactionsas well as the influence of the aqueous environment. Analysis of the products with HPLC, ion-spray MS, HPLC-MS and HPLC-CID-MS revealed that (Tmd)Phe is a highly potent carbene-precursor, which can be transformed easily into uniform crosslinking products by smooth photolysis. However, the electrophilic nature of the intermediate causes a high tendency to react with water molecules. The 4-azidobenzoyl group showed comparable crosslinking efficiency, but the probability to create nonuniform irradiation products (e.g. through rearrangement) is higher, whereas the reaction with water is less dominant. In contrast, Bpa was found to have an extremely low affinity to react with water, whereas prolonged UV irradiation is needed to get complete rearrangement into a variety of products. As the absorption band of alpha-diazocarbonyls at around 350 nm possesses a low extinction coefficient, 2-diazo-3,3,3-trifluoropropionyl-TP5 could not be activated at all with the optimized irradiation conditions that we have chosen for our comparative studies. (C) Munksgaard 1997.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 11/07/20 alle ore 21:13:29