The structural instability of red cells from hereditary spherocytic patients suggests that the primary molecular alteration in this disorder resides in the spectrin membrane skeleton, a macromolecular structure thought to control red cell shape. In this study, the protein composition of HS red cell ghosts, spectrin-depleted inverted vesicles, and spectrin heterodimers was quantitatively normal in 9 HS patients from 3 unrelated families. The binding of 32P-spectrin heterodimers to spectrin-depleted inverted vesicles (physiological ionic strength, pH 7.5, 4°C) indicated a KD of 18.6 ± 2.0 nm (mean ± s.e.) and a maximal binding capacity of 98 ± 7 μg of spectrin bound/mg of inverted vesicle protein for 9 HS patients, and 18.3 ± 1.8 nm and 116 ± 8 μg spectrin/mg of inverted vesicle protein in 9 paired normal controls. Therefore the binding of spectrin to the syndeins (Bands 2.1 → 2.6) its high affinity membrane binding site, is unaltered in hereditary spherocytosis.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cardiology and Cardiovascular Medicine