4-氟色氨酸肌红蛋白和血红蛋白的氟核磁共振谱的测定与分析

Assignment and analysis of fluorine nuclear magnetic resonance spectra of 4-fluorotryptophan myoglobins and hemoglobins.

作者信息

Pearson J G, Montez B, Le H, Oldfield E, Chien E Y, Sligar S G

机构信息

Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana 61801, USA.

出版信息

Biochemistry. 1997 Mar 25;36(12):3590-9. doi: 10.1021/bi961664h.

DOI:10.1021/bi961664h

PMID:9132010

Abstract

We have obtained the 470 MHz 19F NMR spectra of wild type [4-F]Trp-labeled myoglobins (MbCO, MbO2, deoxyMb, metMb, and MbCN) and hemoglobins (HbCO, HbO2, and deoxyHb), as well as those of several mutants (W7F Mb, betaW15F Hb, betaW37S Hb, and betaY130F Hb, all as the carbonmonoxy adducts), prepared via site-directed mutagenesis. The maximum observed chemical shift range induced by folding is 6.4 ppm. Using a multipole shielding polarizability-local reaction field approach, we have computed the electrostatic field contributions to the fluorine shielding. For residues which do not have F atoms in contact with neighboring groups, we find an approximately 1 ppm mean square deviation in shift from experiment, with the R2-like structure of HbCOA being in very close accord with experiment.

摘要

我们已经获得了野生型[4-F]色氨酸标记的肌红蛋白（MbCO、MbO2、脱氧肌红蛋白、高铁肌红蛋白和MbCN）和血红蛋白（HbCO、HbO2和脱氧血红蛋白）以及通过定点诱变制备的几种突变体（W7F Mb、βW15F Hb、βW37S Hb和βY130F Hb，均为一氧化碳加合物）的470 MHz 19F NMR光谱。折叠诱导的最大观测化学位移范围为6.4 ppm。使用多极屏蔽极化率-局部反应场方法，我们计算了静电场对氟屏蔽的贡献。对于没有F原子与相邻基团接触的残基，我们发现与实验相比，位移的平均方差约为1 ppm，HbCOA的R2样结构与实验非常吻合。