EFFECT OF ACETOHYDROXAMIC ACID ON RUMEN UREASE ACTIVITY INVITRO
EFFECT OF ACETOHYDROXAMIC ACID ON RUMEN UREASE ACTIVITY INVITRO
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DOI：
10.3168/jds.s0022-0302(81)82624-0
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发表时间：
1981-01-01
影响因子：
3.5
通讯作者：
NEGI, SS
中科院分区：
文献类型：
--
作者：
MAKKAR, HPS;SHARMA, OP;NEGI, SS
乙酰异羟肟酸，浓度为1 × 10 - 4。10-6 M，6 ×10-5 M和1 ×10-3在体外试验中，M对瘤胃微生物脲酶的抑制率分别为11%、50%和74%。与刀豆脲酶不同，酸对瘤胃脲酶的抑制达到平衡状态。抑制作用在较宽的pH范围（8-10）内最大，并且与瘤胃脲酶的pH活性曲线不相似。巯基化合物没有逆转抑制;在乙酰异羟肟酸添加之前添加这些化合物防止抑制。抑制的性质是非竞争性的，抑制剂常数为4.8 × 104。10-5 M.乙酰异羟肟酸在产生50%的脲酶抑制浓度不影响瘤胃纤维素酶和蛋白水解酶在体外。乙酰异羟肟酸-瘤胃尿素酶复合物在透析条件下是可解离的。[讨论了动物（反刍动物）的尿素饲养。]
Acetohydroxamic acid at a concentration of 1 .times. 10-6 M, 6 .times. 10-5 M and 1 .times. 10-3 M inhibited urease of intact rumen microbes in vitro by 11, 50 and 74%. Inhibition of rumen urease by the acid reached equilibrium state, unlike jack bean urease. Inhibition was maximum over a broad range of pH (8-10) and it did not resemble the pH activity profile of rumen urease. Sulfhydryl compounds did not reverse the inhibition; addition of these compounds prior to acetohydroxamic acid addition prevented inhibition. The nature of inhibition was noncompetitive with inhibitor constant 4.8 .times. 10-5 M. Acetohydroxamic acid at a concentration that produced 50% urease inhibition did not affect rumen cellulase and proteolytic enzymes in vitro. The complex of acetohydroxamic acid-rumen urease is dissociable on dialysis. [Feeding of urea to animals (ruminant) is discussed.].