The binding of glucosylceramidase to glucosylceramide is promoted by its activator protein.
نویسندگان
چکیده
A protein activator of glucosylceramidase (EC 3.2.1.45) has been previously identified by us in human placenta [(1985) Biochim. Biophys. Acta 836, 157-166]. In the present paper we report that its function in vitro is to stimulate the binding of the enzyme to its substrate, glucosylceramide. After the purification step which frees the enzyme of most of its activator protein (octyl-Sepharose 4B chromatography), the capacity of glucosylceramidase to bind to the glucosylceramide micelles is dramatically decreased. The addition of the activator protein to the purified enzyme restores this binding.
منابع مشابه
The carbohydrate moiety of the activator protein for glucosylceramide beta-glucosidase.
SAP-2 is a family of heat-stable, acidic glycoproteins which stimulate enzymatic hydrolysis of glucosylceramide. We studied the carbohydrate moieties of a ConA-binding form of SAP-2. The protein contained glucosamine, galactose, mannose, and fucose; galactosamine and sialic acid were not detectable. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and silver staining showed three bands...
متن کاملThe activator protein for glucosylceramide beta-glucosidase from guinea pig liver. Improved isolation method and complete amino acid sequence.
beta-Glucosidase activator (SAP-2) is a family of heat-stable, acidic glycoproteins which stimulate enzymatic hydrolysis of glucosylceramide. In this study, we improved the purification method and found that SAP-2 is highly heterogeneous. A hot water extract of frozen guinea pig liver was fractionated by ammonium sulfate sedimentation, then chromatographed with DEAE-Sephacel, Sephadex G-75, and...
متن کاملUptake by neuroblastoma cells of glucosylceramide, glucosylceramide glucosidase, its stimulator protein, and phosphatidylserine.
Serum-free cultured neuroblastoma cells (clone NlE-115) have been shown to absorb emulsified glucosylceramide, glucosylceramide glucosidase, an activator protein for the enzyme, and phosphatidylserine from a synthetic medium. Uptake of the enzyme was augmented by phosphatidylserine, and vice versa. Uptake of the enzyme-lipid complex was further augmented by the activator protein. It appears lik...
متن کاملP 144: Sunflower Mannose binding Lectin-Associated Serine Protease Inhibitor-1 (SFMI-1) and -2: Significant Inhibitors of Mannose binding Lectin Pathway which Helps in Multiple Sclerosis Treatment
One of the important parts of innate immunity is complement system that occurs in three different ways; the classic, the alternative and the lectin pathway. The four pattern recognition molecules that have been identified till now are Mannose binding lectin (MBL), a component of lectin pathway, and three ficolins (ficolin1,-2 and -3) which compound to the carbohydrates of the cell surface. MBL ...
متن کاملBlood Coagulation Induced by Iranian Saw-Scaled Viper (Echis Carinatus) Venom: Identification, Purification and Characterization of a Prothrombin Activator
Objective(s): Echis carinatus is one of the venomous snakes in Iran. The venom of Iranian Echis carinatus is a rich source of protein with various factors affecting the plasma protein and blood coagulation factor. Some of these proteins exhibit types of enzymatic activities. However, other items are proteins with no enzymatic activity. Materials and Methods: In order to study the mechanism ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- FEBS letters
دوره 216 2 شماره
صفحات -
تاریخ انتشار 1987