Crystalline Structures of L-Cysteine and L-Cystine: A Combined Theoretical and Experimental Characterization

YANG Y. SU; ETIENNE P. HESSOU; ESTEFANIA COLOMBO; GUSTAVO BELLETTI; ALI MOUSSADIK; IVAN LUCAS; VINCENT FROCHOT; MICHEL DAUDONE; STEPHAN ROUZIERE; DOMINIQUE BAZIN; KE Z. LI; PAOLA QUAINO; FREDERIK TIELENS

Bruselas

Conferencia; 19th International Conference on Density Functional Theory and its Applications (DFT 2022); 2022

It is assumed that genetic diseases affecting the metabolism of cysteine and the kidney function leads to two different kinds of pathologies, cystinuria and cystinosis whereby generate L-cystine crystals. Recently, the presence of L-cysteine crystal has been underlined in the case of cystinosis.1 It can be strikingly seen that cystine ([-S-CH2 -CH-(NH2 )-COOH]2 ) consists of two cysteine (C3H7NO2S) molecules connected by a disulfide (S-S) bond. Therefore, we elucidate the discrepancy between L-cystine and L-cysteine by investigating the theoretical and experimental infrared spectra (IR), X-ray diffraction (XRD) as well as Raman spectra. Results systematically illustrated the presence of functional groups of these two matters which can be apparently distinguished by the S-S and SH bonds. It is probably assumed that L-cystine crystals related to cystinuria and cystinosis as well result from the conversion of L-cysteine. Particularly, drugs carrying SH groups are commonly used, such as cysteamine for the treatment of cystinosis or d-penicillamine and mercaptoporpionylglycine for the treatment of cystinuria. Thereby, our experimental and theoretical data could be of interest to develop new treatments for cystinuria and cystinosis.References1. D. Bazin, M. Daudon, G. André, R. Weil, E. Véron, and G. Matzen, J. Appl. Crystallogr. 2014, 47, 719.2. M. A. Elmonem, K. R. Veys, N. A. Soliman, M. van Dyck, L. P. van den Heuvel, and E. Levtchenko, Orphanet J. Rare Dis. 2016, 11, 1.