Cysteine—gold complexes

NO, Nitrogen oxide, iridium complex, 21 104 NO2SC3H7, L-Cysteine, gold complex, 21 31 NO3C3H7, Serine, copper complex, 21 115 NFPtSe2C24H28, Platinum(II), (A. /V-diethyldi-selenocarbamato)methyl(triphenylphos-phine)-, 21 10... 

Gold complexes of cysteine derivatives such as N-acetylcysteine, penicillamine,... 

Possible metabolites previously suggested include gold complexes of cysteine and glutathione ( ). We have examined solid samples of each of these and find them to fit satisfactorily to a model in which gold is coordinated to two bridging sulfur atoms with bond lengths identical to those found in the chronic sodium gold(I)thiomalate aurosomes. 

Zucconi TD, Janauer GE, Donahe S and Lewkowicz C, Acid dissociation and metal complex formation constants of penicillamine, cysteine, and antiarfiiritic gold complexes at simulated biological conditions,/. Pharm. Sci, 68(4), 426-432 (1979). 

The complex has to be designed in a way that a ligand exchange is possible as for the gold complex in Scheme 1.2 where a chloride ligand is exchanged by the sulfur of the cysteine residue. 

Nolan and coworkers reported the cytotoxicity of different neutral and cationic complexes. The first series of systems studied were Au-IPr derivatives bearing biocompatible moieties such as amino acids (L-proline or L-cysteine, Figure 7.16) [17]. In parallel, a second series of systems was selected, as it is well-known in the literature that cationic gold complexes can induce apoptosis of cancer cell lines. The IC50 were measured with LNCaP (prostate carcinoma) and MDA MB231 (breast carcinoma). 

The vast majority of intravascular gold is protein bound, and most of this (> 85%) is bound to albumin, with the remainder linked to globulin moieties. Gold complexes bind to many proteins with inhibition of activity, and the reactions have been extensively tabulated [10]. Studies on bovine serum albumin (BSA) confirmed, both for AuSTM and AF, that the binding site was the unique cysteine residue, Cys34 [31, 32, 33]. The PEt3 of AF is not lost [32, 33] and the reaction is best considered as a thiol displacement ... 

Chernyak, A. S. and Shestopalova, L.F. (1976) Study of complexes of gold(I) with cysteine in an alkaline medium. Russian Journal of Inorganic Chemistry, English Translation, 21, 464—465. 

Cat B is an abundant and ubiquitously expressed cysteine peptidase of the papain family and makes up a major fraction of lysosomal enzymes that is capable of degrading components of the extracellular matrix in various diseases [30-32]. Cat B is also a prognostic marker for several types of cancer [33], and increased expression and secretion of cat B has been shown to be involved in the migration and invasion of various tumours [34—36], The precise role of cat B in solid tumours is not fully understood, but it has been proposed to participate, along with other cysteine cathepsins, in metastasis, angiogenesis, and tumour progression [37], Indeed, cat B inhibitors reduce both tumour cell motility and invasiveness in vitro [38], Recently, metal complexes based on rhenium, gold and palladium were shown to be effective inhibitors of cat B [39-44],... 

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