Alteration in reactivity of sphingomyelinase from Streptomyces sp. modified with a polyethylene glycol derivative.
Purified sphingomyelinase of Streptomyces A9107 (NRRL 15100) was modified with ss-PEG, methoxypolyethyleneglycol succinimidyl succinate, without loss of activity toward sphingomyelin in the mixed micelles with detergents such as sodium deoxycholate and Triton X-100 or toward a water-soluble, synthetic substrate, HNP, 2-(N-hexadecanoylamino)-4-nitrophenyl phosphocholine. The hemolytic and sphingomyelin-hydrolyzing activities of the enzyme toward intact bovine erythrocyte membrane were completely abolished by modification with ss-PEG, whereas the activity toward membranous sphingomyelin in the erythrocyte ghosts was fully retained. The enzyme activity toward liposomal sphingomyelin (large and small unilamellar vesicles) was significantly decreased by PEG-modification. The thermostability of sphingomyelinase was greatly increased by modification with ss-PEG, whereas the sensitivity of the enzyme to proteolysis was not influenced by that modification.
Matsuyama
H
H
Faculty of Pharmaceutical Sciences, Nagoya City University, Aichi, Japan.
Tomita
M
M
Taguchi
R
R
Ikezawa
H
H
D000818:Animals; D002417:Cattle; D002850:Chromatography, Gel; D010450:Endopeptidases / Q000494:pharmacology; D004910:Erythrocyte Membrane / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D006358:Hot Temperature; D006868:Hydrolysis; D066298:In Vitro Techniques; D008081:Liposomes / Q000737:chemistry; D008823:Micelles; D011092:Polyethylene Glycols / Q000494:pharmacology*; D013108:Sphingomyelin Phosphodiesterase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000494:pharmacology; D013109:Sphingomyelins / Q000097:blood / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology*; D013379:Substrate Specificity; D013388:Succinimides / Q000494:pharmacology*
D008081:Liposomes; D008823:Micelles; D013109:Sphingomyelins; D013388:Succinimides; D011092:Polyethylene Glycols; C069871:methoxypolyethylene glycol succinimidylsuccinate; D013108:Sphingomyelin Phosphodiesterase; D010450:Endopeptidases