[The effect of low molecular weight ligands on relaxation of water protons in protein solutions].
Interaction of low-molecular ligands (LML) isolated from blood serum albumin (SA) and serum proteins leads to higher T1 values for water protons compared with those observed in LML-free solutions, although the total amount of bound water increases. The latter was revealed by low-temperature NMR spectroscopy, as well as by the amount of water sorbed on SA + LML at a relative humidity P/Ps greater than 0.7. In the region 0.2 less than P/Ps less than 0.6 the amount of SA + LML-sorbed water decreased, as compared with that in SA indicating that the oppositely charged groups of LML screen some charged groups of the protein. A decrease of charge-to-charge interactions in solution, or with a high water content, leads to the hydration of those groups. The increase of the T1 value for water protons in solution is, probably, due to a hindered exchange between the sorbed water and bulk water. It is outlined that charge interactions between macromolecules may significantly affect water sorption by proteins.
Aksenov
S I
SI
Bozhenko
V K
VK
Kalachikhina
O D
OD
D001798:Blood Proteins / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D008024:Ligands; D008970:Molecular Weight; D011522:Protons; D014867:Water
D001798:Blood Proteins; D008024:Ligands; D011522:Protons; D014867:Water
Vliianie nizkomolekuliarnykh ligandov na relaksatsiiu protonov vody v rastvorakh belkov.