title: A critical analysis of the use of radiation inactivation to measure the mass of protein.
abstract: Measurements are presented of the radiation inactivation of four enzymes exposed to a 6 MeV proton beam. It has long been thought that the measurement of the susceptibility of an enzyme to ionizing radiation can be used to determine its molecular mass. Results are frequently interpreted using the empirical analysis of Kempner and Macey (Biochim. Biophys. Acta 163, 188-203, 1963). We examine this analysis and discuss the validity and limitations of the assumptions on which it is based. Our results indicate that the specific biochemical properties of each enzyme make a significant contribution to its radiation sensitivity.
authors.affiliation: School of Physics and Space Research, University of Birmingham, Edgbaston, United Kingdom.
authors.forename: D G
authors.initials: DG
authors.lastname: Lidzey
authors.forename: N
authors.initials: N
authors.lastname: Berovic
authors.forename: R S
authors.initials: RS
authors.lastname: Chittock
authors.forename: T D
authors.initials: TD
authors.lastname: Beynon
authors.forename: C W
authors.initials: CW
authors.lastname: Wharton
authors.forename: J B
authors.initials: JB
authors.lastname: Jackson
authors.forename: N S
authors.initials: NS
authors.lastname: Parkinson
mesh_terms: D000818:Animals; D002417:Cattle; D001517:Coleoptera / Q000201:enzymology; D003435:Crotalid Venoms / Q000201:enzymology; D008156:Luciferases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000528:radiation effects*; D008970:Molecular Weight; D009195:Peroxidase / Q000737:chemistry / Q000528:radiation effects*; D011755:Pyrophosphatases / Q000737:chemistry / Q000528:radiation effects*; D014357:Trypsin / Q000737:chemistry / Q000528:radiation effects*; D014361:Trypsin Inhibitors
chemical_list: D003435:Crotalid Venoms; D014361:Trypsin Inhibitors; D009195:Peroxidase; D008156:Luciferases; D014357:Trypsin; D011755:Pyrophosphatases; C021899:nucleotide pyrophosphatase