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Updated: May 25, 2026

Characterization of Sickling During Controlled Automated Deoxygenation with Oxygen Gradient Ektacytometry
Published on: November 5, 2019
Hb S-São Paulo: a new sickling hemoglobin with stable polymers and decreased oxygen affinity
Susan E D C Jorge1, Ariel A Petruk, Elza M Kimura
1Department of Clinical Pathology, School of Medical Sciences, State University of Campinas, Campinas, State of São Paulo, Brazil.
Abstract:
Hb S-São Paulo (SP) [HBB:c.20A>T p.Glu6Val; c.196A>G p.Lys65Glu] is a new double-mutant hemoglobin that was found in heterozygosis in an 18-month-old Brazilian male with moderate anemia. It behaves like Hb S in acid electrophoresis, isoelectric focusing and solubility testing but shows different behavior in alkaline electrophoresis, cation-exchange HPLC and RP-HPLC. The variant is slightly unstable, showed reduced oxygen affinity and also appeared to form polymers more stable than the Hb S. Molecular dynamics simulation suggests that the polymerization is favored by interfacial electrostatic interactions. This provides a plausible explanation for some of the reported experimental observations.
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