Glycation of Aspartate Aminotransferase and Conformational Flexibility
Biochemical and Biophysical Research Communications
Glycation of proteins alters biological function and changes cellular processes. Our study investigated the conformational changes that accompany glycation using the cardiac aspartate aminotransferase (cAAT). We examined the effects of brief and prolonged exposure of cAAT to glyceraldehyde (Glyc) and ribose 5-phosphate (R5P). When cAAT was briefly incubated (3.5 h) with Glyc (500 microM) or R5P (5 mM) at 37 degrees C, cAAT activity and 1-anilinonaphthalene 8-sulfonate (ANS) binding increased relative to control. After prolonged incubation (64 h) with Glyc (500 microM) or R5P (5 mM) at 37 degrees C, activity and ANS binding decreased relative to control. Furthermore, upon prolonged incubation of cAAT with 500 microM Glyc (14.5 h) or 2 mM R5P (64.25 h) at 37 degrees C, the denaturation curves shifted to the right relative to control. We conclude that upon brief incubation with Glyc and R5P, cAAT exhibited a more open and flexible structure and upon prolonged incubation, a more rigid structure.
Anilino Naphthalenesulfonates, Aspartate Aminotransferase, Glyceraldehyde
Seidler NW, Seibel I. Glycation of Aspartate Aminotransferase and Conformational Flexibility. Biochemical and Biophysical Research Communications. 2000; 277(1). doi: 10.1006/bbrc.2000.3626.