title: Fibers, crystals, and other forms of HbS polymers in deoxygenated sickle erythrocytes.
abstract: We have examined by electron microscopy the formation of fibers and crystals from sickle hemoglobin within sickle erythrocytes following deoxygenation during capillary storage from 1 to 132 days. Intracellular fibers were found on the first day and throughout the period of study. The fibers exhibited a diameter (mean +/- SD) of 17.4 +/- 0.62 nm and were aligned in the cell with a fiber-to-fiber spacing of 18.6 nm (x-axis) by 22.7 nm (y-axis). Between 65 and 132 days, extracellular hemoglobin crystals developed, with a lattice periodicity of 9.63 +/- 0.6 nm. Fibers and crystals coexist as separate structures. These results suggest that crystal formation upon storage of packed deoxygenated sickle erythrocytes may proceed via a phase of fiber dissolution followed by hemoglobin reassembly into extracellular crystals, rather than by a progressive alignment and direct fusion of existing fibers.
mesh_terms: D000755:Anemia, Sickle Cell / Q000473:pathology; D003460:Crystallization; D004912:Erythrocytes / Q000648:ultrastructure*; D006451:Hemoglobin, Sickle; D006454:Hemoglobins; D006801:Humans; D008854:Microscopy, Electron; D011108:Polymers; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D006451:Hemoglobin, Sickle; D006454:Hemoglobins; D011108:Polymers; C100003:deoxyhemoglobin