Relaxation study of the backbone dynamics of human profilin by two‐dimensional 1H‐15N NMR

FEBS Letters

Bell, Aneka J.¹  Constantine, Keith L.²  Friedrichs, Mark S.²  Lavoie, Thomas B.¹  Mueller, Luciano²  Metzler, William J.² 

[1] Department of Macromolecular Biochemistry, Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543-4000, USA;Department of Macromolecular NMR, Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, NJ 08543-4000, USA

关键词: Actin-binding protein;    Conformational change;    NMR relaxation;    Order parameter;    Poly-L-proline binding;   

DOI  :  10.1016/0014-5793(93)80855-O

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The dynamic properties of 111 backbone HN sites in uncomplexed human profilin, a protein of 139 residues, have been characterized by two-dimensional inverse-detected ¹H-¹⁵N NMR spectroscopy. Heteronuclear {¹H}-¹⁵N nuclear Overhauser effects and ¹⁵N longitudinal and transverse relaxation rates have been analyzed in terms of model-free spectral density functions and exchange contributions to transverse relaxation rates. Relatively high mobilities on the nanosecond timescale are observed for Asp²⁶ and Ser²⁷, which form part of a loop connecting β-strands A and B, and for Thr⁹² through Ala⁹⁵, which are in a loop connecting β-strands E and F. Significant exchange contributions, indicative of motions on the microsecond to millisecond timescale, have been obtained for 30 residues. These include Leu⁷⁷, Asp⁸⁰ and Gly⁸¹ of a loop between β-strands D and E, Ser⁸⁴ and Met⁸⁵ of β-strand E, Gly¹²¹ of a loop connecting β-strand G and the C-terminal helix, and Gln¹³⁸, which is next to the C-terminal residue Tyr¹³⁹. Some of the regions showing high flexibility in profilin are known to be involved in poly-L-proline binding.

【 授权许可】

Unknown