1H n.m.r. studies of insulin. Assignment of resonances and properties of tyrosine residues.
1H n.m.r. studies of insulin. Assignment of resonances and properties of tyrosine residues.
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1H 核磁共振
DOI：
10.1042/bj2290731
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
V. Ramesh
中科院分区：
文献类型：
--
作者：
J. Bradbury;V. Ramesh
芳香族 1H nmr 的归属报道了牛 2-锌胰岛素的四个酪氨酸残基的共振，基于双共振技术、哈恩自旋回波脉冲序列的使用以及对酪氨酸 A14 和 A19 以及 des-(B26-B30)-胰岛素硝化的特定衍生物的检查。四个酪氨酸残基的滴定曲线显示残基A14和B16在溶液中的正常pK'值为10.3-10.6，这与它们在晶体中的单体和二聚体中对溶剂的可及性一致。酪氨酸残基 A19 和 B26 的 pK' 值为 11.4，并在其滴定曲线中表现出与溶剂可及性有限和非极性环境一致的其他特征。残基 B16 和 B26 的间质子都观察到附近酪氨酸残基（可能是 A19）的滴定。 nmr 的解释在溶液中获得的数据与在胰岛素晶体上获得的单体和二聚体的晶体学数据一致[Blundell, Dodson, Hodgkin & Mercola (1972) Adv.蛋白质化学。 26、279-402]。
The assignment of the aromatic 1H n.m.r. resonances of the four tyrosine residues of bovine 2-zinc insulin is reported, based on double resonance techniques, use of Hahn spin echo pulse sequences and examination of specific derivatives nitrated at tyrosines A14 and A19 as well as des-(B26-B30)-insulin. Titration curves of the four tyrosine residues show that residues A14 and B16 have normal pK' values of 10.3-10.6 in solution, consistent with their accessibility to solvent in monomer and dimer in the crystal. Tyrosine residues A19 and B26 have pK' values of 11.4 and exhibit other features in their titration curves that are consistent with limited accessibility to solvent and a nonpolar environment. The meta protons of residues B16 and B26 both observe the titration of a nearby tyrosine residue, probably A19. Interpretation of the n.m.r. data obtained in solution is consistent with the crystallographic data for the monomer and dimer obtained on insulin crystals [Blundell, Dodson, Hodgkin & Mercola (1972) Adv. Protein Chem. 26, 279-402].