DETERMINATION OF ANGIOTENSINS BY CAPILLARY ELECTROPHORESIS

A protocol to separate ten peptides of the angiotensin family by capil lary electrophoresis was described. The experiment was carried out usi ng the Waters Quanta 4000 Electrophoresis system and the steps taken t o determine the optimum electrophoretic conditions include (i) the use of different electrolytes, (ii) variation of ionic composition and pH of the electrolytes,l(iii) variation of applied voltage and the wavel ength of ultraviolet detection. Successful separation of the ten angio tensin peptides was obtained using a voltage of 10 kV, 0.1 M phosphori c acid (pH 1.95) as electrolyte and ultraviolet detection at 185 nm. T he protocol was then used to follow the metabolism of exogenous angiot ensin I (ANG I) in rat lung homogenate and the separation and identifi cation of an angiotensin peptide in human plasma. In addition to these two applications, the protocol can be use to separate and identify an giotensins and other peptides for which specific antibodies have yet t o be developed.