A circular dichroism and fluorescence quenching study of the interactions between rhodium(II) complexes and human serum albumin

Various divalent rhodium complexes Rh 2(L) 4 (L = acetate, propionate, butyrate, trifluoroacetate and trifluoroacetamidate) have been found to bind to non-defatted human serum albumin (HSA) at molar ratios about 8:1. The circular dichroism measurements showed that the more liposoluble carboxylates,...

Full description

Saved in:
Bibliographic Details
Published in:Journal of inorganic biochemistry 1999-05, Vol.75 (1), p.55-61
Main Authors: Espósito, Breno Pannia, Faljoni-Alário, Adelaide, de Menezes, Jorge Fernando Silva, de Brito, Hermi Felinto, Najjar, Renato
Format: Article
Language:English
Subjects:
Antineoplastic Agents - chemistry
Circular Dichroism
Fluorescence quenching
Human serum albumin
Humans
Rhodium - chemistry
Rhodium(II)
Serum Albumin - chemistry
Spectrometry, Fluorescence
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Various divalent rhodium complexes Rh 2(L) 4 (L = acetate, propionate, butyrate, trifluoroacetate and trifluoroacetamidate) have been found to bind to non-defatted human serum albumin (HSA) at molar ratios about 8:1. The circular dichroism measurements showed that the more liposoluble carboxylates, butyrate and trifluoroacetate, caused the major alterations of the secondary structure of HSA. Stern-Volmer constants for the fluorescence quenching of the buried Trp214 residue by these complexes were also higher for the lipophilic metal compounds. In the case of the rhodium carboxylates it was observed that their denaturating and quenching properties could be explained in terms of their liposolubilities: the higher their lipophilic characters, the higher their abilities to penetrate inside the protein framework leading to structural alterations, and the closer they could get to the Trp residue causing fluorescence quenching. The liposoluble amidate complex, Rh 2 (tfc) 4, presented an intermediate quenching and did not cause structural alterations in the protein, presumably not penetrating inside the peptidic backbone. This study shows that it is possible to design new antitumor metal complexes which bind, to a large extent, to a transport protein causing little structural damage.
ISSN:0162-0134
1873-3344
DOI:10.1016/S0162-0134(99)00032-X