STRUCTURES OF DEOXY AND OXY HEMERYTHRIN AT 2.0-A RESOLUTION
STRUCTURES OF DEOXY AND OXY HEMERYTHRIN AT 2.0-A RESOLUTION
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DOI：
10.1016/0022-2836(91)90703-9
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发表时间：
1991-04-05
影响因子：
5.6
通讯作者：
STENKAMP, RE
中科院分区：
文献类型：
--
作者：
HOLMES, MA;LETRONG, I;STENKAMP, RE
在2.0 μ m分辨率下对脱氧和氧代血红蛋白的晶体结构进行了分析，以扩展这种氧结合蛋白的生理形式的低分辨率视图。约束最小二乘精修产生的分子模型给出的R值分别为16.8%（脱氧）（41，064次反射，从10 μ m至2.0 μ m）和17.3%（氧化血红素）（40，413次反射，从10.0 μ m至2.0 μ m）。每种衍生物中的蛋白质结构与肌红蛋白和各种甲硫氨酸形式的血红蛋白非常相似。每个衍生物中的双核复合物保留了桥接两个铁原子的氧原子，但在脱氧血红蛋白中发现的键长支持这样的想法，即在这种形式下，桥被质子化，即桥接基团是羟基。在向氧代血红蛋白的转化中，分子氧与脱氧血红蛋白中的五配位铁原子结合。原子间的距离与所提出的机制是一致的，其中来自桥连基团的质子被转移到结合的双氧，通过在过氧基团和桥连氧原子之间形成氢键将其稳定在过氧氧化态。
The crystallographic structure analyses of deoxy and oxy hemerythrin have been carried out at 2.0 Å resolution to extend the low resolution views of the physiological forms of this oxygen-binding protein. Restrained least-squares refinement has produced molecular models givingR-values of 16.8% for deoxy (41,064 reflections from 10 Å to 2.0 Å) and 17.3% for oxy hemerythrin (40,413 reflections from 10.0 Å to 2.0 Å). The protein structure in each derivative is very similar to that of myohemerythrin and the various met forms of hemerythrin. The binuclear complex in each derivative retains an oxygen atom bridging the two iron atoms, but the bond lengths found in deoxy hemerythrin support the idea that, in that form, the bridge is protonated, i.e. the bridging group is a hydroxyl. Dioxygen binds to the pentaco-ordinate iron atom in deoxy hemerythrin in the conversion to oxy hemerythrin. The interatomic distances are consistent with the proposed mechanism where the proton from the bridging group is transferred to the bound dioxygen, stabilizing it in the peroxo oxidation state by forming a hydrogen bond between the peroxy group and the bridging oxygen atom.