Adachi K, Kikugawa K, Asakura T
Biochim Biophys Acta. 1983 Feb 15;742(3):597-606. doi: 10.1016/0167-4838(83)90278-9.
Sickle hemoglobin (Hb S) was cross-linked by two types of bifunctional imidoesters, dimethyladipimidate (DMA) and dimethyl-3,3'-dithiobispropionimidate (DTBP). These modified hemoglobins were separated into monomer, dimer and polymer fractions by gel filtration. All of these modified hemoglobins showed extremely left-shifted oxygen equilibrium curves with no cooperativity. The stabilities of these hemoglobins were also decreased. The solubilities of these modified hemoglobins in high-phosphate buffers were lower than those of native Hb S. Studies on the kinetics of the aggregation of these modified hemoglobins showed that intracross-linked Hb S with DMA and DTBP (DMA- and DTBP-modified monomeric Hb S) still retained the capability of aggregation with a delay time, while intercross-linked Hb S with DMA and DTBP (DMA- and DTBP-modified oligomeric Hb S) aggregated without a delay time. When the kinetics of aggregation was measured for mixtures of modified and native deoxy-Hb S, DMA-modified monomeric deoxy-Hb S shortened the delay time prior to aggregation of native deoxy-Hb S. The other modified deoxy-Hb S did not affect the delay time, suggesting that these modified oligomeric hemoglobins neither participate in the formation of nuclei nor copolymerize with native deoxy-Hb S.
镰状血红蛋白（Hb S）通过两种双功能亚胺酯，即己二酸二甲酯（DMA）和二甲基-3,3'-二硫代双丙酰亚胺酯（DTBP）进行交联。通过凝胶过滤将这些修饰的血红蛋白分离为单体、二聚体和聚合物组分。所有这些修饰的血红蛋白均显示出极度左移的氧平衡曲线，且无协同性。这些血红蛋白的稳定性也有所降低。这些修饰的血红蛋白在高磷酸盐缓冲液中的溶解度低于天然Hb S。对这些修饰的血红蛋白聚集动力学的研究表明，用DMA和DTBP进行内交联的Hb S（DMA和DTBP修饰的单体Hb S）仍保留延迟聚集的能力，而用DMA和DTBP进行外交联的Hb S（DMA和DTBP修饰的寡聚Hb S）则无延迟地聚集。当测量修饰的和天然的脱氧Hb S混合物的聚集动力学时，DMA修饰的单体脱氧Hb S缩短了天然脱氧Hb S聚集前的延迟时间。其他修饰的脱氧Hb S不影响延迟时间，这表明这些修饰的寡聚血红蛋白既不参与核的形成，也不与天然脱氧Hb S共聚。
