Changes in enzymatic and membrane-adsorbing activities of sphingomyelinase from Bacillus cereus by modification with a polyethylene glycol derivative.
Sphingomyelinase (SMPLC) from Bacillus cereus was modified with a polyethylene glycol (PEG) derivative, methoxypolyethylene glycol-succinimidyl succinate (ss-PEG). The molecular weight of the ss-PEG-modified SMPLC was calculated to be approx. 150 kDa by gel-filtration whereas that of the native enzyme, was 25 kDa. By this modification, the enzyme increased its thermostability and retained its hydrolytic activity toward 2-(N-hexadecanoylamino)-4-nitrophenylphosphocholine (HNP) and sphingomyelin (SM) in the mixed micelles with the surfactants such as Triton X-100 and sodium deoxycholate (SDC). However, the activity toward liposomal SM was significantly decreased, and all the enzyme activities toward bovine erythrocytes, including membraneous SM-hydrolyzing and hemolytic activities as well as the enzyme adsorption onto the erythrocyte membranes, were completely lost.
Matsuyama
H
H
Faculty of Pharmaceutical Sciences, Nagoya City University, Aichi, Japan.
Tomita
M
M
Taguchi
R
R
Ikezawa
H
H
D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology*; D002417:Cattle; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology; D011092:Polyethylene Glycols; D013108:Sphingomyelin Phosphodiesterase / Q000737:chemistry / Q000378:metabolism*
D011092:Polyethylene Glycols; D013108:Sphingomyelin Phosphodiesterase