Studies on the cholinesterase forms present in the ascitic fluid of Ehrlich tumour

Cholinesterase activity was detected in the ascitic fluid of Ehrlich tumour and studied in a comparative manner in relation to that found in mice plasma. Enzymes from both sources were characterized with respect to optimum pH, substrate concentration and quinidine inhibition. After gel filtration by Sephadex G-200 and Sepharose 6B, two enzyme forms were observed in ascitic fluid as well as in mice plasma: a large form (L) and a small form (S) presenting molecular weights of 191 000, and 224 000 daltons for L forms and 71 000 and 69 000 daltons for S forms respectively. Concanavalin A interacts with both molecular forms, suggesting a glycoprotein nature for these enzymes.