Quick Search:

uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-14352

Ruiz-Sánchez, P; Mundwiler, S; Spingler, B; Buan, N R; Escalante-Semerena, J C; Alberto, R (2008). Syntheses and characterization of vitamin B12-Pt(II) conjugates and their adenosylation in an enzymatic assay. Journal of Biological Inorganic Chemistry, 13(3):335-347.

[img] PDF - Registered users only
1MB

View at publisher

Abstract

Aiming at the use of vitamin B12 as a drug delivery carrier for cytotoxic agents, we have reacted vitamin B12 with trans-[PtCl(NH3)2(H2O)]+, [PtCl3(NH3)](-) and [PtCl4](2-). These Pt(II) precursors coordinated directly to the Co(III)-bound cyanide, giving the conjugates [(Co)-CN-(trans-PtCl(NH3)2)]+ (5), [(Co)-CN-(trans-PtCl2(NH3))] (6), [(Co)-CN-(cis-PtCl2(NH3))] (7) and [(Co)-CN-(PtCl3)](-) (8) in good yields. Spectroscopic analyses for all compounds and X-ray structure elucidation for 5 and 7 confirmed their authenticity and the presence of the central "Co-CN-Pt" motif. Applicability of these heterodinuclear conjugates depends primarily on serum stability. Whereas 6 and 8 transmetallated rapidly to bovine serum albumin proteins, compounds 5 and 7 were reasonably stable. Around 20% of cyanocobalamin could be detected after 48 h, while the remaining 80% was still the respective vitamin B12 conjugates. Release of the platinum complexes from vitamin B12 is driven by intracellular reduction of Co(III) to Co(II) to Co(I) and subsequent adenosylation by the adenosyltransferase CobA. Despite bearing a rather large metal complex on the beta-axial position, the cobamides in 5 and 7 are recognized by the corrinoid adenosyltransferase enzyme that catalyzes the formation of the organometallic C-Co bond present in adenosylcobalamin after release of the Pt(II) complexes. Thus, vitamin B12 can potentially be used for delivering metal-containing compounds into cells.

Citations

14 citations in Web of Science®
15 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

2 downloads since deposited on 06 Mar 2009
0 downloads since 12 months

Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
DDC:540 Chemistry
Language:English
Date:March 2008
Deposited On:06 Mar 2009 10:21
Last Modified:27 Nov 2013 22:09
Publisher:Springer
ISSN:0949-8257
Publisher DOI:10.1007/s00775-007-0329-4
PubMed ID:18060564

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page