Immunochemical comparison of L-asparaginases from Serratia marcescens and Escherichia coli

Immunochemical properties of l-asparaginases from Serratia marcescens and Escherichia coli were compared by means of quantitative precipitin reactions and quantitative microcomplement-fixation reactions employing homologous and heterologous antisera. The enzyme preparations used in these tests produced one arc of precipitate upon immunoelectrophoresis. According to our results with the precipitin and micro-complement fixation reactions, both enzymes are related immunochemically. On the basis of these tests, distinct structural differences exist between the two enzymes. From results with the micro-complement fixation test, we estimated that the two enzymes could differ by 10 to 15 amino acid residues.