Xenobiotics Research Unit, Biological and Health Sciences Center, The Pontifical Catholic University of Paraná, Brazil.
J Microbiol Methods. 2011 Mar;84(3):461-6. doi: 10.1016/j.mimet.2011.01.020. Epub 2011 Jan 21.
This study aimed to evaluate the influence of different redox potentials (Eh) on cell growth, whole-cell protein profile and cell surface hydrophobicity (CSH) of Candida albicans SC5314. The yeast was grown in YNB broth enriched with reducing (158mM sodium sulfite, 4mM sodium sulfite, 2.5mM sodium metabisulfite, 1.3mM 2-mercaptoethanol, 5.5mM thioglycolic acid, and 3.2mM l-cysteine hydrochloride) and oxidizing agents (15mM ammonium persulfate and 80mM potassium ferricyanide) and incubated in normoxic and anoxic atmospheres at 37°C, for 48h. Pre- and post-incubation Eh values were determined and cytoplasm proteins were extracted. Proteins were parted by SDS-PAGE and their profiles were compared. 3.2mM l-cysteine and 1.3mM 2-mercaptoethanol promoted and maintained negative Eh values during incubation. No differences were detected among SDS-PAGE profiles. CSH differences only were observed with 4mM sodium sulfite and 3.2mM l-cysteine. Results showed that 3.2mM l-cysteine is a reducing agent that allows maintenance of negative Eh in both anoxic and normoxic conditions and it seems not to interfere in the global expression of plasmatic proteins.
本研究旨在评估不同氧化还原电位（Eh）对白色念珠菌 SC5314 细胞生长、全细胞蛋白图谱和细胞表面疏水性（CSH）的影响。酵母在 YNB 肉汤中生长，其中含有还原剂（158mM 亚硫酸钠、4mM 亚硫酸钠、2.5mM 偏重亚硫酸钠、1.3mM 2-巯基乙醇、5.5mM 硫代甘油酸和 3.2mM l-半胱氨酸盐酸盐）和氧化剂（15mM 过硫酸铵和 80mM 铁氰化钾），并在 37°C 下在常氧和缺氧环境中孵育 48 小时。测定预孵育和后孵育的 Eh 值，并提取细胞质蛋白。蛋白质通过 SDS-PAGE 分离，并比较其图谱。3.2mM l-半胱氨酸和 1.3mM 2-巯基乙醇在孵育过程中促进并维持负 Eh 值。SDS-PAGE 图谱之间没有差异。只有 4mM 亚硫酸钠和 3.2mM l-半胱氨酸观察到 CSH 差异。结果表明，3.2mM l-半胱氨酸是一种还原剂，可在缺氧和常氧条件下维持负 Eh 值，并且似乎不会干扰质膜蛋白的全局表达。
