Volume 270,
Number 6,
Issue of February 10, 1995 pp. 2708-2715
©1995 by The American Society for Biochemistry and Molecular Biology, Inc.
Effect of
Hemoglobin Concentration on Nucleation and Polymer Formation in Sickle
Red Blood Cells
(Received for publication, August 3, 1994; and in revised form, November 18, 1994)
James D.
Corbett
,
William E.
Mickols
,
Marcos F.
Maestre
We have used differential polarization imaging microscopy to
measure the amount and orientation of aligned sickle hemoglobin polymer
in quickly deoxygenated sickle red blood cells. Images of the angular
orientation of the aligned polymer at each point in the cell allowed
for determination of the inclination of individual domains, providing
detailed information regarding the polymerization and elongation of
sickle hemoglobin polymers ex vivo. We found that the number
of aligned polymer domains increased with increasing mean cell
hemoglobin concentration. Sickle and holly leaf-shaped cells contained
single or few domains of aligned polymer, while more compact cells such
as irreversibly sickled cells contained many domains. A new class of
cells was discovered by examination of images of the angular
orientation of aligned polymer, which contained a single central
nucleation site, with growth of polymer occurring outward in all
directions in a spherulite-like domain.