Studies on the Destruction of Red Blood Cells. VIII. Molecular Orientation in Sickle Cell Hemoglobin Solutions. ∗

Summary

1. In the oxygen unsaturated state the abnormal sickle cell hemoglobin molecules undergo orderly orientation, forming-by specific linkage of the individual molecules-long chains of hemoglobin elements. Subsequent parallel alignment of these elements results in birefringent tactoids.

2. The birefringent sickled erythrocyte is in all probability a membrane-covered hemoglobin tactoid.

3. The clinical and pathologic manifestations of sickle cell disease apparently follow as a consequence of the effects of the abnormal hemoglobin molecules upon the physical behavior of the erythrocytes.

We are grateful to Dr. W. B. Castle and Dr. T. H. Ham for valuable counsel during this work and the preparation of this manuscript. David F. Waugh, Associate Professor of Physical Biology at the Massachusetts Institute of Technology, aided in demonstrating the anisotropy of the sickled cells and of the hemoglobin tactoids and gave advice concerning the interpretation of the meaning of the toxoid form.