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：1973
卷号：70
期号：12
页码：3604-3608
DOI：10.1073/pnas.70.12.3604
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Possible orientations of deoxyhemoglobin S molecules within sickle-cell fibers are delimited by polarized absorption measurements on single sickled cells and single crystals of deoxyhemoglobin A. The polarization ratio of cells provides a lower limit for that of an individual fiber and, coupled with the absorption properties of the deoxyhemoglobin molecule, restricts the orientation of the long molecular (x) axis to within 22{degrees} of the fiber axis. Adopting the stacked ring model of Finch et al. for the molecular positions and the additional constraint that at least one mutated ({beta}6) site is part of an intermolecular contact, our optical result requires that the true molecular dyad (y) axis pass through some part of an adjacent molecule in the same ring. This range of orientations for the y axis is approximately perpendicular to those described in existing models and places at least one {beta}6 residue in position to be part of a contact between molecules in the same ring.
关键词：anemia ; linear dichroism ; microspectrophotometry ; deoxyhemoglobin A crystals
