Figure 7.

Protection of glutamine synthetase by peptides. Inactivation of the enzyme was measured at doses of irradiation from 0 to 30 kGy. The inactivation curve was fit to a first-order process by regression analysis with Prism for Windows version 5 (GraphPad Software, La Jolla, CA, USA). The fit equation was then used to extrapolate to the irradiation dose required for a 50% loss of activity (half-inactivation). When added, DEHGTAVMLK was 1.0 mM and HMHMHM was 1.7 mM, giving a total of 10 mM of amino acid residues.