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Relaxation study of the backbone dynamics of human profilin by two‐dimensional 1 H‐ 15 N NMR
Author(s) -
Constantine Keith L.,
Friedrichs Mark S.,
Bell Aneka J.,
Lavoie Thomas B.,
Mueller Luciano,
Metzler William J.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)80855-o
Subject(s) - heteronuclear molecule , chemistry , relaxation (psychology) , nuclear magnetic resonance spectroscopy , nuclear overhauser effect , nanosecond , crystallography , microsecond , nuclear magnetic resonance , helix (gastropod) , stereochemistry , physics , ecology , snail , biology , psychology , social psychology , laser , astronomy , optics
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 1 H‐ 15 N NMR spectroscopy. Heteronuclear { 1 H}‐ 15 N nuclear Overhauser effects and 15 N 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 Asp 26 and Ser 27 , which form part of a loop connecting β‐strands A and B, and for Thr 92 through Ala 95 , 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 Leu 77 , Asp 80 and Gly 81 of a loop between β‐strands D and E, Ser 84 and Met 85 of β‐strand E, Gly 121 of a loop connecting β‐strand G and the C‐terminal helix, and Gln 138 , which is next to the C‐terminal residue Tyr 139 . Some of the regions showing high flexibility in profilin are known to be involved in poly‐L‐proline binding.