Imamura T, Fujita S, Ohta Y, Hanada M, Yanase T
J Clin Invest. 1969 Dec;48(12):2341-8. doi: 10.1172/JCI106200.
During the course of a survey, a new hemoglobin, designated hemoglobin Yoshizuka, has been encountered in a Japanese family. Clinically, mild anemia was noted in five of six heterozygous individuals but no other significant abnormalities were found. Hemoglobin Yoshizuka is characterized by the substitution of aspartic acid for asparagine at the tenth residue of the G helix in the beta-chain. Reduced oxygen affinity with almost normal heme-heme interaction was found to be a property of this abnormal hemoglobin. The asparagine residue G10(108)beta lies in the internal cavity of the tetrameric molecule and its main chain carbonyl is thought to be hydrogen bonded to histidine G10(103)alpha at the region of contact between alpha- and beta-chains. It would appear likely that the introduction of a carboxyl group into the central cavity might result in interactions between the polar groups and the substituted side chain, disrupting the system of hydrogen bonds which contribute to the stability of the contacts between unlike subunits.
在一项调查过程中，在一个日裔家族中发现了一种新的血红蛋白，命名为吉冢血红蛋白。临床上，6名杂合子个体中有5名出现轻度贫血，但未发现其他明显异常。吉冢血红蛋白的特征是β链G螺旋第10位残基处天冬酰胺被天冬氨酸取代。已发现这种异常血红蛋白具有氧亲和力降低但血红素-血红素相互作用几乎正常的特性。天冬酰胺残基G10(108)β位于四聚体分子的内腔，其主链羰基被认为在α链和β链接触区域与组氨酸G10(103)α形成氢键。似乎向中心腔引入羧基可能导致极性基团与取代侧链之间的相互作用，破坏有助于不同亚基间接触稳定性的氢键系统。
