Remote access and automation at SSRL
A. González, Aina E. Cohen, Ashley M. Deacon, Therese Eriksson, Scott E. McPhillips, M. Soltis, Hsui Chui, Pete Dunten, Michael Hollenbeck, Irimpan I. Mathews, M. Miller, Timothy McPhillips, Penjit Moorhead, P.H. Phizackerley, Nicholas K. Sauter, Chad J. Smith, Jisoo Song, Henry van den Bedem, Y. Tsai · Acta Crystallographica Section A Foundations of Crystallography · 2011
Structure-property investigation of crystalline amino acids is an important challenge since interactions between individual molecular fragments or even structural domains in the structure can simulate interactions in more complicated biological systems such as proteins and peptides.Besides, crystalline amino acids are applied as drugs, as piezoelectric and nonlinear optical materials.Therefore understanding a crystal structure response to variation in temperature and pressure is significant in such applications.Cysteine is a remarkable amino acid because its side-chain residue contains a sulfhydryl group involved in formation of additional labile hydrogen bonds (S-H…S or S-H…O).The presence of these very weak bonds in the structure allows cysteine to take a peculiar place between hydrophobic (no contribution of side-chains to H-bonds) and hydrophilic amino acids (with that contribution).In the present contribution we discuss an evolution of chiral and racemic cysteine crystal structures on cooling and on increasing pressure followed by X-ray crystallography and Raman spectroscopy.We also compare their behavior with that of cysteine crystalline salts and derivatives.The study was supported by the Projects of RAS (21.44, 5.6.4),SB RAS (Projects 13 & 109), grants from RFBR (09-03-00451, 10-03-00252), a BRHE grant from the CRDF (RUX0-008-NO-06) and FASI (RF) Contracts No GK P2529 & 16.740.11.0166.