Enzymes protective of oxidative damage present in all decades of life in the trabecular meshwork, as detected by two-dimensional gel electrophoresis protein maps.

Our purpose was to determine whether there are age-related differences in the presence of enzymes protective against oxidative damage in normal human trabecular meshwork (TM). The study was also done to determine whether there are significant changes in proteins related to age, gender, or position around the circumference of the meshwork. Human TM was dissected from both eyes of 16 normal donors ranging in age from 9 to 91 years. Proteins were mapped with two-dimensional (2D) gel electrophoresis. The microanalytical method used allowed analysis of samples as small as one fourth of a single meshwork. Selected proteins were identified by Western blot. Superoxide dismutase (SOD) and glutathione reductase were present in all ages on the 2D maps. Age-related changes in the TM were not apparent, although slight differences may exist between juvenile and adult TM, since differences in the relative intensities of some polypeptides were evident. In any single quadrant of the TM, > or = 160 protein spots could be counted visually. The 2D maps of the various quadrants were very similar, and the protein patterns were analogous between fellow eyes. Distinct differences were noted between maps from TM and adjacent cornea and sclera. Other protein spots identified included actin, albumin, transferrin, and vimentin. The TM samples had a mean cellular protein content of 66.3 +/- 15.4 micrograms.