PARTIAL-PURIFICATION AND FURTHER CHARACTERIZATION OF THE NOVEL ENDOGLUCOSAMINIDASE FROM HUMAN SERUM THAT HYDROLYZES METHYLUMBELLIFERYL-N-ACETYL-BETA-D-CHITOTETRAOSIDE (MU-TACT HYDROLASE)

A novel endoglucosaminidase, originally described by Den Tandt et al. [Int. J. Biochem. 20 (1988), 713-719] and bearing the provisional name MU-TACT hydrolase, was purified from human serum 56,000-fold by means of ammonium sulphate precipitation, anion-exchange chromatography, Co n A-Sepharose chromatography and gel filtration on Sepharose CL-6B fol lowed by Superose 12 HR. Based on the latter technique the native appa rent molecular weight of the enzyme appeared to be equal to that of my oglobin, being approx. 17 kD. The enzyme eluted clearly at a different volume than lysozyme. MU-TACT is a commercially available substrate f or lysozyme. For unknown reasons two major peptides co-purify that giv e bands on SDS-PAGE of 55-60 and 31 kD, respectively.