Molecular Mass and Volume in Radiation Target Theory

• Published in: Biophysical journal Vol. 78; no. 4; pp. 1698 - 1702
• Main Authors: Osborne, James C., Miller, Jay H., Kempner, E.S.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-04-2000; Biophysical Society
• Subjects: Animals; Biophysical Phenomena; Biophysics; Cattle; Chickens; Glyceraldehyde-3-Phosphate Dehydrogenases - chemistry; Glyceraldehyde-3-Phosphate Dehydrogenases - radiation effects; In Vitro Techniques; Macromolecular Substances; Molecular biology; Molecular Weight; Muramidase - chemistry; Muramidase - radiation effects; Proteins - chemistry; Proteins - radiation effects; Rabbits; Radiation; Serum Albumin, Bovine - chemistry; Serum Albumin, Bovine - radiation effects
• ISSN: 0006-3495; 1542-0086
• DOI: 10.1016/S0006-3495(00)76721-X

Radiation target analysis is based on the action of ionizing radiation directly on macromolecules. Interactions of this radiation with the molecules leads to considerable structural damage and consequent loss of biological activity. The radiation sensitivity is dependent on the size of the macromolecules. There has been confusion and discrepancy as to whether the molecular mass or the molecular volume was the determinant factor in the sensitivity. Some proteins are known to change their hydrodynamic volume at low pH, and this characteristic can be utilized to compare the radiation sensitivities of these proteins in the two states. The results show that the radiation sensitivity of proteins depends on the mass of the molecule and is independent of the molecular volume/shape.