Specific binding of Cu(II) ions by leucine-enkephalin analogs.
J Inorg Biochem
; 60(1): 21-9, 1995 Oct.
Article
en En
| MEDLINE
| ID: mdl-7595469
Results are reported from a potentiometric and spectroscopic (UV-visible, CD, and ESR) of the protonation constants and Cu(II)-complex stability constants of leucine enkephalin amide (H-Tyr-Gly-Gly-Phe-Leu-NH2, Leu-EN-amide) and two nitro analogs having 4-nitro substituent on the phenyl ring of the Phe residue, (H-Tyr-Gly-Gly-Phe(NO2)-LeuNH2, Leu-EN(nitro)- amide) and the other one with a sarcosine residue replacing the Gly3 residue (Leu-ENSar-amide). Over the pH range of 6-8.5, Leu-EN-amide interacts more strongly with Cu(II) than does the methionine analog, forming a more stable complex with three nitrogens coordinated. The Sar residue acts as a "breakpoint" to the formation of 3N or 4N complexes and, as a result, causes the formation of dimeric complexes bonded through the amino-N, a deprotonated peptide-N- and deprotonated Tyr-O- donors.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Encefalina Leucina
/
Cobre
Idioma:
En
Revista:
J Inorg Biochem
Año:
1995
Tipo del documento:
Article
País de afiliación:
Polonia
Pais de publicación:
Estados Unidos