Watkins L M, Rodriguez R, Schneider D, Broderick R, Cruz M, Chambers R, Ruckman E, Cody M, Mrachko G T
Department of Chemistry and Biochemistry, Southwest Texas State University, 601 University Dr., San Marcos, TX 78666, USA.
Arch Biochem Biophys. 2003 Jul 1;415(1):14-23. doi: 10.1016/s0003-9861(03)00230-3.
2-(2(')-Hydroxyphenyl)benzenesulfinate desulfinase (HPBS desulfinase) catalyzes the cleavage of the carbon-sulfur bond of 2-(2(')-hydroxyphenyl)benzenesulfinate (HPBS) to form hydroxybiphenyl and sulfite. This is the final step in the desulfurization of dibenzothiophene, the organosulfur compound used to study biodesulfurization of petroleum middle distillate. HPBS desulfinase was purified 1600-fold from Rhodococcus IGTS8. The purification was monitored using a spectrofluorimetric assay and SDS-PAGE. The pI of HPBS desulfinase is 5.6, the temperature optimum is 35 degrees C, and the pH optimum is 7.0. HPBS desulfinase has a K(m) of 0.90+/-0.15 microM and a k(cat) of 1.3+/-0.07 min(-1). Several analogs were tested for their ability to act as substrates or inhibitors of HPBS desulfinase. No alternative substrates and very few inhibitors were identified. HPBS desulfinase activity decreases in the presence of Cu(2+) and Zn(2+), while no metals significantly enhance enzyme activity. HPBS desulfinase is susceptible to tyrosine, tryptophan, and cysteine specific modification agents.
2-(2′-羟基苯基)苯亚磺酸盐脱亚磺基酶（HPBS脱亚磺基酶）催化2-(2′-羟基苯基)苯亚磺酸盐（HPBS）的碳-硫键断裂，形成羟基联苯和亚硫酸盐。这是二苯并噻吩脱硫的最后一步，二苯并噻吩是一种用于研究石油中间馏分生物脱硫的有机硫化合物。HPBS脱亚磺基酶从红球菌IGTS8中纯化了1600倍。纯化过程通过荧光光谱法测定和SDS-PAGE进行监测。HPBS脱亚磺基酶的pI为5.6，最适温度为35℃，最适pH为7.0。HPBS脱亚磺基酶的K(m)为0.90±0.15μM，k(cat)为1.3±0.07 min(-1)。测试了几种类似物作为HPBS脱亚磺基酶底物或抑制剂的能力。未发现替代底物，仅鉴定出极少数抑制剂。在Cu(2+)和Zn(2+)存在下，HPBS脱亚磺基酶活性降低，而没有金属能显著增强酶活性。HPBS脱亚磺基酶对酪氨酸、色氨酸和半胱氨酸特异性修饰剂敏感。
