Abstract

HERNANDEZ BETANCOURT, Oscar et al. Changes in the biological activity of an antigen due to the temperature generated during the polyacrylamide electrophoresis. Rev Cubana Invest Bioméd [online]. 2006, vol.25, n.3. ISSN 0864-0300.

The effect of temperature on the biological activity of an antigen during the electrophoresis in non-reducing polyacrylamide gels was evaluated because on occasions the technique precedes electroelution, a method used in the purification of certain proteins. The prostate specific antigen was utilized for the assay. It was purified starting from the semen of voluntary patients. It was precipitated with ammonium sulfate 70 %. The repetitions (3 for each temperature) were made at 4 and 25 °C and at 20 mA. For every tested temperature, the fragments from the gels cut at the expected size for the specific prostatic antigen (33 kDa) were electroeluted at 4 °C. By comparing the protein concentrations using Lowry’s technique and the radioimmunoenzymatic method, it was quantified the amount of biologically active protein after the electrophoresis. A commercial prostate specific antigen was used as control. The results indicate that at 4 °C the antigen keeps 80 % of its biological activity, which does not occur at 25 °C, where more than 50 % of the protein is biologically inactive.

Keywords : PSA; temperature; electrophoresis..