REACTIONS OF O-2 WITH HEMERYTHRIN, MYOGLOBIN, AND HEMOCYANIN - EFFECTS OF D2O ON EQUILIBRATION RATE CONSTANTS AND EVIDENCE FOR H-BONDING
REACTIONS OF O-2 WITH HEMERYTHRIN, MYOGLOBIN, AND HEMOCYANIN - EFFECTS OF D2O ON EQUILIBRATION RATE CONSTANTS AND EVIDENCE FOR H-BONDING
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DOI：
10.1021/ic00238a008
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发表时间：
1986-08-27
影响因子：
4.6
通讯作者：
SYKES, AG
中科院分区：
文献类型：
--
作者：
ARMSTRONG, GD;SYKES, AG
用温度跃变法和停流法测定了O2与血红蛋白（Phascolopsis gouldii的八聚体）、肌红蛋白（抹香鲸）和血蓝蛋白（Panulirus interruptus的单体）结合的开和关速率常数。当H20被D20替代时，观察到以下效果：降低19%;肌红蛋白，kon降低17%，kofr降低16%;血蓝蛋白，kon和koff不变。这些影响是一致的氢键作用的情况下，氧形式的血红蛋白和肌红蛋白，但不是在血蓝蛋白的情况下。所获得的结果支持最近提出的用于在血红蛋白活性位点处结合02的结构。
On and off rate constants associated with the binding of 02 to hemerythrin (octamer from Phascolopsis gouldii), myoglobin (sperm whale), and hemocyanin (monomer from Panulirus interruptus) havebeen determined by using the temperature-jump and stopped-flow methods. When H20 is replaced by D20, the following effects are observed: hemerythrin, km unchanged, ko!! 19% decrease; myoglobin, k „17% decrease, kofr 16% decrease; hemocyanin, kon and koff unchanged. These effects are consistent with H-bonding effects in the case of the oxy forms of hemerythrin and myoglobin but not in the case of hemocyanin. The results obtained support the recently proposed structure for binding of 02 at the hemerythrin active site.