Hydrolysis of phosphoric acid diesters by snake venom phosphodiesterase and 5'-nucleotide diesters of sinapis alba germs via and covalently enzyme-bound intermediate

Snake venom phosphodiesterase from $\text{Crotalus}\text{durissus}$$\text{terrificus}$ and 5′-nucleotide phosphodiesterase from $\text{Sinapis}\text{alba}$ were incubated with the 1-naphthyl ester of 5′-methyl-³H]thymidylic acid. After short-time incubation the enzymes were denatured by extraction into phenol and chromatographed on Sephadex G-25. Protein fractions containing radioactivity were collected, dialysed and subjected to ultra-thin-layer isoelectric focussing and autoradiography. The results obtained indicate a hydrolytic course via a covalently-bound intermediate.