Preparation and proton nuclear magnetic resonance investigation of cross-linked mixed valency hybrid hemoglobins: models for partially oxygenated species.
Preparation and proton nuclear magnetic resonance investigation of cross-linked mixed valency hybrid hemoglobins: models for partially oxygenated species.
复制标题
交联混合价杂合血红蛋白的制备和质子核磁共振研究：部分含氧物质的模型。
作者：
Miura,S;Ho,C
Shigetoshi Miura 和 Chien Ho* 摘要：以下交联混合价杂合血红蛋白是由血红蛋白 C (j86Glu-Lys) 和人类正常成人血红蛋白的衍生物制备而成：(«+ CN/?) A («/3) CXL、(«/^ cn) a («0) cXL、(a+ 0i^)^) cXL 和 (a/3+ CN) A (a+ CN/3) cXL，其中下标A和C分别表示β二聚体来自人类正常成人血红蛋白和突变血红蛋白C，XL表示交联血红蛋白。这些单氧碳形式的价杂合血红蛋白根据 Walder 等人的方法通过双 (3, 5-二溴水杨基) 富马酸酯交联。 [Walder, J. A., Zaugg, R. H., Walder, R. Y., Steel, J. M., & Koltz, I. M.(1979) Biochemistry 18, 4265-4270], It X 射线晶体学表明，这种双功能试剂在两条 ß 链的 82 位处的两个赖氨酸残基之间交联，从而跨越 2, 3-二磷酸甘油酸结合位点，并且交联的血红蛋白在其氧结合中协同作用 [Walder, J. A., Walder, R. Y „& Amone, A.(1980) J. Mol. Biol. [141, 195-216]，已经获得了这些混合血红蛋白在 H2G 低场 7 至 20 ppm 光谱范围内的超精细位移和可交换质子核磁共振谱。每个四聚体具有一个氰基链的混合血红蛋白可以作为单连接物种的模型，而具有两个氰基链的混合血红蛋白可以作为双连接中间体的模型。血红蛋白 (a+ CN/? C0) A 中的铁链脱氧时，协同现象，通常称为血红蛋白 (Hb) 1 中的“血红素-血红素”相互作用，在过去二十年中一直是深入研究的主题，有两种通用模型被用来描述 Hb 的协同氧化，其中一种称为两种状态协同机制 [例如，参见 Monod 等人]。 al.(1965)]和另一种称为顺序机制[例如，参见 Koshland 等人(1966)]，尽管对 Hb 分子投入了大量精力，但研究人员尚未完全理解或同意 Hb 协同氧化的详细分子机制。有关该主题的最新讨论，请参阅 Shulman 等人(1975, 1982)、Fung 等人。等人（1976，1977），Perutz（1976，1979），Viggiano＆Ho（1979），Viggiano等人（1979），Pettigrew等人（1980），Ho＆Russu（1981），Johnson＆Ackers（1982）和Ho等人（1982）。
Shigetoshi Miura and Chien Ho* abstract: The following cross-linked mixed valency hybrid hemoglobins have been prepared from derivatives of hemo-globin C (j86Glu—Lys) and human normal adult hemoglobin:(«+ CN/?) A («/3) CXL,(«/^ cn) a («0) cXL,(a+ 0i^)^) cXL, and (a/3+ CN) A (a+ CN/3) cXL, where subscripts A and C denote that the ß dimers are from human normal adult hemoglobin and mutant hemoglobin C, respectively, and XL denotes cross-linked hemoglobin. These valency hybrid hemoglobins in the carbon monoxy form are cross-linked by bis (3, 5-dibromosalicyl) fumarate according to the procedure of Walder et al.[Walder, J. A., Zaugg, R. H., Walder, R. Y., Steel, J. M., & Koltz, I. M.(1979) Biochemistry 18, 4265-4270], It has been shownby X-ray crystallography that this bifunctional reagent cross-links between the two lysine residues of the two ß chains at position 82, thereby spanning the 2, 3-diphosphoglycerate binding site, and that the cross-linked hemoglobin is cooperativein its binding of oxygen [Walder, J. A., Walder, R. Y „& Amone, A.(1980) J. Mol. Biol. 141, 195-216], Proton nuclear magnetic resonance spectra of the hyperfine shifted and exchangeable proton resonances for these hybrid hemoglobins over the spectral region from 7 to 20 ppm downfield from H2Ghave been obtained. Thehybrid hemo-globins with one cyanomet chain per tetramer can serve as models for singly ligated species and those with two cyanomet chains can serve as models for doubly ligated intermediates during the cooperative oxygenation of hemoglobin. Upon deoxygenation of the ferrous chains in (a+ CN/? C0) A-The cooperative phenomenon, commonly known as the “heme-heme” interaction in hemoglobin (Hb), 1 has been the subject of intensive research during the past two decades. There are two general models which havebeen used to describe the cooperative oxygenation of Hb, one known as a two-state concerted mechanism [for example, see Monod et al.(1965)] and the other known as a sequential mechanism [for example, see Koshland et al.(1966)]. Despite considerable effort de-voted to the Hb molecule, the detailed molecular mechanism for the cooperative oxygenation of Hb is neither fully un-derstood nor agreed upon by researchers. For recent discus-sions on this topic, refer to Shulman et al.(1975, 1982), Fung et al.(1976, 1977), Perutz (1976, 1979), Viggiano & Ho (1979), Viggiano et al.(1979), Pettigrew et al.(1980), Ho & Russu (1981), Johnson & Ackers (1982), and Ho et al.(1982).