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Title
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The haem-accessibility in leghaemoglobin of Lupinus luteus as observed by proton magnetic relaxation.
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Authors
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S.Vuk-pavlović,
B.Benko,
S.Maricić,
G.Lahajnar,
I.P.Kuranova,
B.K.Vainshtein.
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Ref.
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Int J Pept Protein Res, 1976,
8,
427-434.
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PubMed id
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Abstract
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Using the solvent-protons' longitudinal magnetic relaxation rates (p.m.r.) for
Lupinus luteus leghaemoglobin derivatives the accessibility of the haem has been
evaluated by our "stereo-chemical p.m.r. titration" method with nonexchangeable
protons of aliphatic lower alcohols in otherwise deuterated solutions. The haem
in leghaemoglobin is more accessible and its protein environment more flexible
compared with vertebrate haemoglobins. The correlation time in
aquometleghaemglobin aqueous solution has been determined by measuring the
frequency dispersion of the p.m.r. rates between 6.1 and 93 MHZ. Taking into
account the measured value of tauc = (7.7 +/- 0.5 x 10(-10) s the iron-to-proton
inter-spin distances have been calculated. The significance of these distances
as well as the electronic g-factor anisotrophy for elucidation of fine
structural details of the haem-environment are discussed.
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