Published In

Proceedings of the National Academy of Sciences

Document Type

Article

Publication Date

1-1-1977

Subjects

Hemoglobin S, Electron microscopy, Sickle cell, Helical fibers, Reconstructed image

Abstract

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, 718-7221 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.

Rights

https://creativecommons.org/publicdomain/mark/1.0/

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U. S. C. §1734 solely to indicate this fact.

Persistent Identifier

https://archives.pdx.edu/ds/psu/42733

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