Hb Long Island: a hemoglobin variant with a methionyl extension at the NH2 terminus and a prolyl substitution for the normal histidyl residue 2 of the beta chain.
Hb Long Island: a hemoglobin variant with a methionyl extension at the NH2 terminus and a prolyl substitution for the normal histidyl residue 2 of the beta chain.
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Hb Long Island：一种血红蛋白变体，在 NH2 末端具有甲硫氨酰延伸，并用脯氨酰取代了 β 链的正常组氨酰残基 2。
DOI：
10.1073/pnas.82.14.4602
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发表时间：
1985
影响因子：
11.1
通讯作者：
Shih,DT
中科院分区：
文献类型：
--
作者：
Barwick,RC;Jones,RT;Head,CG;Shih,MF;Prchal,JT;Shih,DT
Hb Long Island was found in a diabetic man and his nondiabetic mother as the result of a routine clinical measurement of Hb AIc. It is present in amounts approximately equal to Hb A. Its alpha chains are normal but its beta chains have two alterations compared to the normal. A methionyl residue is attached to the usual NH2-terminal valyl residue. This valyl residue is followed by prolyl residue in place of the usual histidyl residue 2. The remaining sequence of the beta chain is normal. No hemoglobin or abnormal beta chain containing only the prolyl substitution could be detected by several different electrophoretic and HPLC procedures. We postulate that Hb Long Island is the result of a mutation in which a single nucleotide change causes the substitution of a prolyl residue for the normal histidyl residue at position 2 of the beta chain. We further postulate that this abnormal prolyl residue inhibits enzymatic cleavage of the initiator methionyl residue from the abnormal beta chain during posttranslational processing. Although the oxygen affinities of the whole blood, suspended cells, and hemolysate are normal, the affinity of the isolated Hb Long Island is slightly decreased and the effects of organic phosphates are reduced compared to normal. These changes are consistent with the loss of the normal histidyl residue 2 and the extension of the NH2-terminal end of the beta-chain molecule.
