TY - JOUR
T1 - Hemoglobins Austin and Waco
T2 - Two Hemoglobins with substitutions in the α1β2 contact region
AU - Moo-Penn, Winston F.
AU - Johnson, Mary H.
AU - Bechtel, Katherine C.
AU - Jue, Danny L.
AU - Therrell, Bradford L.
AU - Schmidt, Robert M.
N1 - Funding Information:
1 Use of trade names is for identification only and does not constitute endorsement by the U.S. Public Health Service or by the U.S. Department of Health, Education, and Welfare. z Address correspondence to W. Moo-Penn.
PY - 1977/2
Y1 - 1977/2
N2 - Hemoglobins (Hbs) Austin and Waco were detected by their electrophoretic migration on cellulose acetate (pH 8.4) and citrate agar (pH 6.2). By these methods, both variants migrated between Hbs A and F. Globin chain analysis at pH 8.6 indicated that the mutant β chain of Hb Austin was faster moving than the βA chain; however, the mutant chain of Hb Waco was indistinguishable from the βA chain by this technique. The two variants were isolated by ion-exchange column chromatography. Sequence studies demonstrated a substitution of serine (Hb Austin) and lysine (Hb Waco) for arginine at position 40 in the β chain. These mutations involve an amino acid residue in the α1β2 contact region, which, before this report, had been considered invariant in all hemoglobin sequences. Hb Austin was found to exist as dimers when oxygenated and as tetramers when deoxygenated. The equilibrium constant (Kd) for the tetramer to dimer transition was approximately 300 × 10-6 m, as calculated from sedimentation velocity studies. This variant also had high oxygen affinity, a much reduced heme-heme interaction, and a normal Bohr effect. The functional properties of Hb Waco were similar to those of Hb A.
AB - Hemoglobins (Hbs) Austin and Waco were detected by their electrophoretic migration on cellulose acetate (pH 8.4) and citrate agar (pH 6.2). By these methods, both variants migrated between Hbs A and F. Globin chain analysis at pH 8.6 indicated that the mutant β chain of Hb Austin was faster moving than the βA chain; however, the mutant chain of Hb Waco was indistinguishable from the βA chain by this technique. The two variants were isolated by ion-exchange column chromatography. Sequence studies demonstrated a substitution of serine (Hb Austin) and lysine (Hb Waco) for arginine at position 40 in the β chain. These mutations involve an amino acid residue in the α1β2 contact region, which, before this report, had been considered invariant in all hemoglobin sequences. Hb Austin was found to exist as dimers when oxygenated and as tetramers when deoxygenated. The equilibrium constant (Kd) for the tetramer to dimer transition was approximately 300 × 10-6 m, as calculated from sedimentation velocity studies. This variant also had high oxygen affinity, a much reduced heme-heme interaction, and a normal Bohr effect. The functional properties of Hb Waco were similar to those of Hb A.
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U2 - 10.1016/0003-9861(77)90089-3
DO - 10.1016/0003-9861(77)90089-3
M3 - Article
C2 - 14597
AN - SCOPUS:0017333342
VL - 179
SP - 86
EP - 94
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -