Sakakibara S, Yamaguchi K, Hosokawa Y, Kohashi N, Ueda I
Biochim Biophys Acta. 1976 Feb 13;422(2):273-9. doi: 10.1016/0005-2744(76)90138-8.
Cysteine oxidase (cysteine dioxygenase, EC 1.13.11.20) was purified approximately 1000-fold from rat liver. The purified enzyme (protein-B) was obtained as an inactive form, which was activated by anaerobic preincubation with L-cysteine. The active form of protein-B was inactivated during aerobic incubation to produce cysteine sulfinate. This inactivation of protein-B was protected by a distinct protein in rat liver cytoplasm, namely stabilizing protein (protein-A). The Ka and Km values for L-cysteine were 0.8-10(-3) M and 1.3-10(-3) M respectively. The enzyme was strongly inhibited by Cu+ and/or Fe2+ chelating agents but not by Cu2+ chelating agent. The optimum pH of enzyme reaction was 8.5-9.5 while that of enzyme activation was 6.8-9.5, with a broad peak.
半胱氨酸氧化酶（半胱氨酸双加氧酶，EC 1.13.11.20）从大鼠肝脏中纯化出来，纯化倍数约为1000倍。纯化后的酶（蛋白B）以无活性形式获得，通过与L-半胱氨酸进行厌氧预孵育可使其激活。蛋白B的活性形式在有氧孵育过程中失活，生成半胱氨酸亚磺酸盐。蛋白B的这种失活受到大鼠肝脏细胞质中一种独特蛋白质即稳定蛋白（蛋白A）的保护。L-半胱氨酸的Ka和Km值分别为0.8×10⁻³ M和1.3×10⁻³ M。该酶受到Cu⁺和/或Fe²⁺螯合剂的强烈抑制，但不受Cu²⁺螯合剂的抑制。酶反应的最佳pH值为8.5 - 9.5，而酶激活的最佳pH值为6.8 - 9.5，呈宽峰状。
