Hydrolysis of sulfur-containing peptides promoted by palladium (II) complexes

Citation
Xm. Luo et al., Hydrolysis of sulfur-containing peptides promoted by palladium (II) complexes, PROG NAT SC, 9(12), 1999, pp. 909-915
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Multidisciplinary
Journal title
PROGRESS IN NATURAL SCIENCE
ISSN journal
1002-0071 → ACNP
Volume
9
Issue
12
Year of publication
1999
Pages
909 - 915
Database
ISI
SICI code
1002-0071(199912)9:12<909:HOSPPB>2.0.ZU;2-X
Abstract
H-1 NMR is used to monitor the hydrolysis of methionine- and cysteine-conta ining peptides, promoted by palladium (II) diaqua complexes. The cleavage r eaction is somewhat sequence-selective, Comparing the hydrolytic rates of M et-as bond promoted by different palladium (II) complexes, it is found that they have the following sequence: trans-[Pd(Py)(2)(H2O)(2)](2+) > cis-[Pd( en) (H2O)(2)](2+) much greater than cis-[Pd(N, S-MetH)(H2O)(2)](2+). Based on H-1 NMR, electrospray mass spectrometry and kinetic data, a new mononucl ear active complex for cleavage is proposed. In the active form, palladium( II) coordinates to substrates through thioether, deprotonated amide nitroge n and amide oxygen of methionyl residue, forming a fused six-membered and f ive-membered complex, and the Met-aa band in it is cleaved by external atta ck of solvent water. It is the first time to find that the Cys-Pro bond is fast cleaved with the half-lives of 50 min at 40 degrees C. The new finding may have practical application in site-specific cleavage of Cys-Pro contai ning peptides and proteins.