1.Facile synthesis of cysteine and triethanolamine capped CdTe nanoparticles.
Mntungwa N1, Pullabhotla VS, Revaprasadu N. Colloids Surf B Biointerfaces. 2013 Jan 1;101:450-6. doi: 10.1016/j.colsurfb.2012.07.010. Epub 2012 Jul 28.
Cysteine and triethanolamine capped CdTe nanoparticles have been synthesized using a simple aqueous solution based method. This method involves the reaction of tellurium powder with sodium borohydride (NaBH(4)) in water to produce telluride ions (Te(2-)), followed by the simultaneous addition of an aqueous solution of cadmium chloride or other cadmium source (acetate, carbonate and nitrate) and solution of L-cysteine ethyl ester hydrochloride or triethanolamine. The effect of capping agent on the size, structure and morphology of the as-synthesized nanoparticles was investigated. The particles were characterized using optical spectroscopy, transmission electron microscopy (TEM), high-resolution TEM (HRTEM), X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy.
2.Preparation and properties of S-nitroso-L-cysteine ethyl ester, an intracellular nitrosating agent.
Clancy R1, Cederbaum AI, Stoyanovsky DA. J Med Chem. 2001 Jun 7;44(12):2035-8.
In this report, a protocol for the preparation of the hydrochloride of S-nitroso-L-cysteine ethyl ester (SNCEE.HCl; 2) is presented. The synthesis of 2 has been targeted because S-nitroso-L-cysteine (SNC; 2b), which is extensively used for trans-S-nitrosation of thiol-containing proteins, has a limited ability of crossing cellular membranes. The nitrosothiol 2 was prepared via direct S-nitrosation of the hydrochloride of L-cysteine ethyl ester (CEE.HCl; 1a) with ethyl nitrite. 2 is relatively stable in crystal form and when neutralized to SNCEE (2a) in aqueous solutions treated with chelators of metal ions. Traces of metal ions, however, triggered the decomposition of 2a to nitric oxide and a S-centered radical, which were detected by ESR spectrometry. In contrast to 2b, 2a is a lipophilic compound that was taken up by human neutrophils. The latter process was paralleled by inhibition of the NADPH oxidase-dependent generation of superoxide anion radicals, presumably via reaction(s) of intracellular trans-S-nitrosation.
3.The solid-state molecular structure of the S-nitroso derivative of L-cysteine ethyl ester hydrochloride.
Yi J1, Khan MA, Lee J, Richter-Addo GB. Nitric Oxide. 2005 Jun;12(4):261-6.
Nitrosation of protein sulfhydryl groups to form thionitrites (S-nitrosothiols) has been reported to be important in the biochemistry of nitric oxide. Such S-nitrosation of protein thiol residues has been shown to alter the function of some proteins. In this brief communication, we report the X-ray crystal structure of S-nitroso-L-cysteine ethyl ester hydrochloride. Two rotamers with respect to the NCCS moiety are present in the crystal: the major rotamer is in the gauche+ conformation, and the minor rotamer is in the rare anti (trans, antiperiplanar) conformation for a cysteinyl compound. Importantly, the CSNO groups for both rotamers are in the syn (cis, synperiplanar) form. To the best of our knowledge, this is the first reported high-resolution solid-state structure of an S-nitroso derivative of a cysteine or cysteinyl-containing compound.
4.Ultraviolet A regulates the stemness of human adipose tissue-derived mesenchymal stem cells through downregulation of the HIF-1α via activation of PGE(2)-cAMP signaling.
Lee J1, Jung E, Hyun JW, Park D. J Cell Biochem. 2012 Dec;113(12):3681-91. doi: 10.1002/jcb.24241.
Ultraviolet A (UVA) irradiation is responsible for a variety of changes in cell biology. The purpose of this study was to investigate the effects of UVA irradiation on the stemness properties of human adipose tissue-derived mesenchymal stem cells (hAMSCs). Furthermore, we examined the UVA-antagonizing effects of L-cysteine ethylester hydrochloride (ethylcysteine) and elucidated its action mechanisms. The results of this study showed that UVA reduced the proliferative potential and stemness of hAMSCs, as evidenced by reduced proliferative activity in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and downregulation of OCT4, NANOG, and SOX2, stemness-related genes. The mRNA level of hypoxia-inducible factor (HIF)-1α, but not HIF-2α was reduced by UVA. Moreover, the knockdown of HIF-1α using small interfering RNA (siRNA) for HIF-1α was found to downregulate stemness genes, suggesting that UVA reduces the stemness through downregulation of HIF-1α.