Affonso O R, Mitidieri E
An Acad Bras Cienc. 1976;48(3):591-5.
In this study it was shown that the rat blood serum xanthine oxidase (X.O.) is differently inhibited by -SH reagents and seems that the blood serum enzyme has two types of -SH groups, one reacting relatively rapidly and unrelated to the enzyme activity and the other reacting slowly to produce inactivation. The results presented suggest that there are only few fundamental relationship between the different -SH reagents used and the inhibition of the enzyme activity in the blood serum. With mercurials it was shown that the most reactive -SH groups of the rat blood serum are not related to the X.O. activity, but when sufficient number are reacted the enzyme is structurally altered so that inhibition appears. With oxidants such as iodine the inhibition of the X.O. activity of rat blood serum seems to be not related specifically with the oxidation of -SH groups.
本研究表明，大鼠血清黄嘌呤氧化酶（X.O.）受 -SH 试剂的抑制情况不同，血清酶似乎有两类 -SH 基团，一类反应相对较快且与酶活性无关，另一类反应缓慢并导致失活。研究结果表明，所用的不同 -SH 试剂与血清中酶活性的抑制之间仅有很少的基本关系。对于汞剂，研究表明大鼠血清中反应性最强的 -SH 基团与 X.O. 活性无关，但当有足够数量的基团发生反应时，酶的结构会发生改变从而出现抑制作用。对于碘等氧化剂，大鼠血清 X.O. 活性的抑制似乎与 -SH 基团的氧化并无特定关联。
