Binding of a spin‐labeled phenylalanine analog to sickle hemoglobin: EPR and NMR studies

FEBS Letters

Lu, Hwei-Zu¹  Johnson, Michael E.¹  Currie, Bruce L.¹ 

[1] Department of Medicinal Chemistry and Pharmacognosy, 545 Pharmacy Building, University of Illinois at Chicago, PO Box 6998, Chicago, IL 60680, USA

关键词: Hemoglobin;    Sikle;    EPR;    NMR;    Spin label;    Competitive binding;    Hb;    hemoglobin;    COHb;    carbonmonoxy liganded ferrous Hb;    metHb;    ferric Hb;    HbA;    normal adult Hb;    HbS;    sickle Hb;    Tempone;    2;    2;    6;    6-tetrameth-yl-4-oxopiperidone-1-oxyl;    SL-Phe;    N-(2;    2;    5;    5-tetramethylpyrrolidin-1-oxyl-3-carboxyl)-L-phenylalanine t-butyl ester;    Phe;    phenylalanine;    Cys;    cysteine;    Bis-Tris;    [bis(2-hydroxyethyl)imino]tris(hydroxymethyl)methane;   

DOI  :  10.1016/0014-5793(84)81059-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We have synthesized a spin-label analog of phenylalanine as a competitive inhibitor probe of the sickle hemoglobin aggregation process. Sickle hemoglobin gelation measurements indicate that the spin-label phenylalanine analog is a potent inhibitor of deoxy sickle hemoglobin aggregation. We have also used spin label EPR and high-resolution proton NMR to study the interaction of the phenylalanine analog with hemoglobin, and find that the kinetic off-rate is comparable to, or slower than the hemoglobin rotational rate (i.e., ⪸ 10⁸ s⁻¹), and that at least one, and perhaps two significant localized interaction region(s) exist within a few angstroms of the β chain N- and C-termini. Correlation with other known structural information suggests that the observed interaction sites may be relevant to the mechanism for inhibition of sickle hemoglobin aggregation.

【 授权许可】

Unknown