title: Comparative intermolecular cross-relaxation studies of human hemoglobin in red blood cells and bovine serum albumin in solution.
abstract: Intermolecular cross-relaxation rate (CR) spectra [1/T(IS) (HDO) or 1/T(IS) (H(2) O) vs f(2) (ppm) profiles] for bovine serum albumin [BSA; molecular weight (MW), 66 kDa] solution, partially hydrolyzed BSA gel (BSA*gel) and packed human red blood cells (RBCs) with normal or unstable hemoglobin (Hb; MW, 65 kDa) were studied using f(2) irradiation ranging from - 100 to 100 ppm at γH(2) /2π of 250 Hz. The CR spectra for BSA*gel (pD 4.01, 0.10 M NaCl, 4.83 and 14.39%) exhibited different features in the off-resonance region (below - 2.00 and above 12.0 ppm) relative to that for BSA solution (pD 7.14, 0.10 M NaCl, 14.39%), indicating the association of BSA* molecules in the gel state. The CR spectrum for packed RBCs was compared with those for BSA*gel and BSA solution (14.39%) by correcting for differences in protein concentration. The corrected CR spectrum for packed normal RBCs in the off-resonance region was similar to that for BSA solution, indicating that the physical characteristics of Hb in normal RBCs may be in a solution-like state. Our results on normal RBCs were approximately consistent with the previously reported thermodynamic and hydrodynamic findings that Hb in RBCs and/or in concentrated solution seems to be in a suspension of hard scaled particles.
authors.affiliation: Department of Physiology and Biophysics, Gifu University Graduate School of Medicine, Gifu, Japan. era@gifu-u.ac.jp
authors.forename: Seiichi
authors.initials: S
authors.lastname: Era
authors.forename: Masaru
authors.initials: M
authors.lastname: Sogami
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Uyesaka
authors.forename: Kazuo
authors.initials: K
authors.lastname: Kato
authors.forename: Masataka
authors.initials: M
authors.lastname: Murakami
authors.forename: Shigeru
authors.initials: S
authors.lastname: Matsushima
authors.forename: Yasutomi
authors.initials: Y
authors.lastname: Kinosada
mesh_terms: D000818:Animals; D002417:Cattle; D004912:Erythrocytes / Q000378:metabolism*; D005782:Gels; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D012996:Solutions
chemical_list: D005782:Gels; D006454:Hemoglobins; D012996:Solutions; D012710:Serum Albumin, Bovine