Related Experiment Videos
The three-dimensional structure of sickle hemoglobin macrofibers
Progress in Clinical and Biological Research
|January 1, 1987
Summary
Sickle cell hemoglobin (HbS) macrofibers form before HbS crystallization. A 3D structural analysis reveals antiparallel rows of double strands, forming a detailed electron density model.
Area of Science:
- Biophysics
- Structural Biology
- Hematology
Background:
- Deoxygenated sickle cell hemoglobin (HbS) forms macrofibers preceding crystallization.
- These macrofibers are helical structures with alternating narrow and wide regions.
Purpose of the Study:
- To present a three-dimensional structural analysis of HbS macrofibers.
- To elucidate the detailed arrangement of double strands within HbS macrofibers.
Main Methods:
- Three-dimensional image reconstructions of HbS macrofibers.
- Fourier filtering and analysis of electron micrographs.
- Cross-correlation analysis with known crystal structures.
- Computation of a 3D electron density model using atomic coordinates.
Main Results:
- HbS macrofibers comprise 5 antiparallel rows of double strands.
- Asymmetric disposition of outer rows creates characteristic "notches".
- Computed Fourier transforms show spacings similar to the Wishner-Love crystal.
- 3D electron density model accurately reproduces observed macrofiber features.
Conclusions:
- The detailed 3D structure of HbS macrofibers has been determined.
- The findings provide insights into the mechanism of sickle cell hemoglobin crystallization.
- The study establishes a structural basis for understanding HbS aggregation and fiber formation.