期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1977
卷号：74
期号：12
页码：5538-5542
DOI：10.1073/pnas.74.12.5538
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Aggregated forms of deoxyhemoglobin S were examined with a field emission transmission electron microscope. Images of isolated helical fibers were obtained from sickled cell lysates stained directly on the electron microscope grid. Optical and digital analyses of the electron micrographs showed that the fibers are similar to those characterized by J. T. Finch, M. F. Perutz, J. F. Bertles, and J. Dobler [(1973) Proc. Natl. Acad. Sci. USA 70, 718-722] in that they consist of stacked discs each composed of six hemoglobin molecules. The fibers exhibit an outer diameter of 160-170 A and an inner diameter of about 60 A with an axial spacing of 58 A per disc. The fiber can be described as a helix consisting of 56 discs per helical turn. We observed discs of six hemoglobin molecules, which may be stable substructural components of the fibers. They were observed in preparations of hemoglobin fibers and exhibited 6-fold symmetry by power spectrum analysis. A reconstructed image of a disc digitally filtered for 6-fold symmetry has a maximum external diameter of [~]170 A and a central hole of 60 A diameter and is similar to the axial projection of a single disc from a low-resolution, three-dimensional reconstructed model of a fiber.
