Saposin B (SAP-B) is a small, non-enzymatic glycosphingolipid activator protein essential for the lysosomal degradation of cerebroside sulfates (sulfatides). It functions as a biological detergent, physically extracting target lipid molecules from biological membranes to form a soluble, transportable protein-lipid complex. This presentation renders the substrate accessible to the hydrolytic enzyme arylsulfatase A (ARSA). Deficiencies or genetic mutations in the prosaposin gene leading to a loss of functional Saposin B result in Saposin B deficiency, a rare lysosomal storage disease phenotypically resembling metachromatic leukodystrophy (MLD).

Key Research & Assay Applications

• Enzyme Replacement & Activity Assays: Ideal as a functional cofactor for reconstituting in vitro arylsulfatase A degradation kinetics and lipid editing mechanics.
• Immunology & NKT Cell Activation: Used in downstream investigations profiling phospholipid transfer dynamics and lipid antigen presentation to Natural Killer T (NKT) cells.
• Drug Discovery Support: High-value target component for screening therapeutics, small molecules, or chaperone designs aiming to mitigate metachromatic leukodystrophy pathways.

Product Features & Specifications

• Expression System: Engineered and produced in an optimized Escherichia coli (E. coli) bacterial expression platform.
• Tag Status: Expressed as an N-terminal His-tag fusion and purified using proprietary chromatography steps, followed by site-specific proteolytic cleavage to yield a completely tag-free final protein.
• Sequence Profile: Comprises the native 79-amino acid mature Saposin B sequence (GDVCQDCIQM...CDE).
• High Purity: Formulated to >90% purity as verified by Coomassie blue staining on SDS-PAGE.
• Buffer Formulation: Supplied at a concentration of 0.5 – 2.0 mg/mL in 25 mM Phosphate Buffer, pH 7.2, 75 mM NaCl, and 50% Glycerol for premium structural stability.

Catalog Number: SAPB-301 | This product is intended for laboratory research use only (RUO). Long-term storage is recommended at -20°C.