The mechanism of inactivation of S-adenosylhomocysteinase by 2'-deoxyadenosine.
The mechanism of inactivation of S-adenosylhomocysteinase by 2'-deoxyadenosine.
复制标题
2-脱氧腺苷灭活S-腺苷高半胱氨酸酶的机制。
DOI：
10.1016/0006-291x(80)90829-3
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发表时间：
1980
影响因子：
3.1
通讯作者：
Fish,S
中科院分区：
文献类型：
--
作者：
Abeles,RH;TashjianJr,AH;Fish,S
S-腺苷高半胱氨酸酶（SAHase）被2′-脱氧腺苷不可逆地灭活（Hirshfield，MS（1979）J.Biol.Chem.254，22-25）。在失活过程中，2′ dAd与酶紧密结合，即不能通过凝胶过滤或透析去除。失活伴随着酶结合NAD的减少。当失活的酶变性时，没有2′ dAd被回收。分离出相当于约80%结合2′ dAd的腺嘌呤。推测2′-脱氧腺苷首先被酶结合的NAD氧化为3′-酮基-2-脱氧腺苷。3′酮基活化C-2′上的氢，促进腺嘌呤的消除。
S-Adenosylhomocysteinase (SAHase) is irreversibly inactivated by 2′-deoxyadenosine (Hirshfield, MS (1979) J. Biol. Chem. 254, 22–25). In the course of this inactivation, 2′ dAd becomes tightly bound to the enzyme, ie, cannot be removed by gel filtration or dialysis. Inactivation is accompanied by reduction of the enzyme bound NAD. When the inactivated enzyme is denatured, no 2′ dAd is recovered. Adenine equivalent to about 80% of the bound 2′ dAd is isolated. It is proposed that 2′-deoxyadenosine is first oxidized to 3′-keto-2-deoxyadenosine by enzyme bound NAD. The 3′ keto group activates the hydrogen at C-2′ and facilitates elimination of adenine.