Endoglycoceramidase (EGCase) cleaves the linkage between oligosaccharides and cer-amides of various glycosphingolipids [Ito, M. & Yamagata, T. (1986) J. Biol. Chem. 261, 14278-14282]. A detergent was required for EGCase to express full activity, possibly due to its hydrophobic nature. Recently, activator proteins responsible for stimulating EGCase activity in the absence of detergents were isolated from the culture supernatant of Rhodococcus sp. [Ito, M., Ikegami, Y., & Yamagata, T. (1991) J. Biol. Chem. 266, 7919-7926]. The activity of activator II specific for EGCase II was heat-labile but insensitive to trypsin-treatment. This activator (69.2 kDa) was converted to the 27.9 kDa polypeptide via the 42 kDa intermediate by exhaustive trypsination, and the stimulatory activity of 27.9 kDa polypeptide on EGCase II was identical to that of the native form toward asialo GM, and cell-surface GM3 of horse erythrocytes as substrates. This observation was successfully applied to obtain the purified activator without contamination with EGCase activity, which is abolished completely following treatment with trypsin.
|Number of pages||5|
|Journal||Journal of Biochemistry|
|Publication status||Published - Jan 1 1991|
All Science Journal Classification (ASJC) codes
- Molecular Biology