Based on the comprehensive membrane protein production platform established through years of experience, scientists form Creative Biostructure can offer tailored Mempro™ saposin production services by detergent-free expression system.
Saposin is a small lysosomal protein which acts as activating agent of various lysosomal lipid-degrading enzymes. Saposin possibly reacts on the enzymes by secluding the lipid substrate from the membrane ambient, therefore letting it more approachable to the soluble degradative enzymes.
The mammalian saposins are produced as a prosaposin, in which there are two Saposin-A domains and four Saposin-B domains. However, in other proteins, a number of Saposin-B domains also occurred, the majority of them are active in the lysis of membranes. The main structure of the prosaposin protein is shown in the following sketch map, figuring the N- and C-terminal SapA domains and the four SapB1 and four SapB2 domains. Proteolytic split of the proprotein takes place in the grey regions. After the proteolytic process of prosaposin, contiguous pairs of SapB1 and SapB2 domains remain connected.
Figure 1. The main structure of prosaposin protein. (Structure, 2005)
Figure 2. Crystal structure of human saposin C dimer in an open conformation. (Structure, 2008)
Creative Biostructure has rich professional experience in high quality saposin production using detergent-free membrane protein expression system, we can perform various strategies for Mempro™ detergent-free protein production, including:
Nanodiscs can preserve target membrane proteins solubilized, moreover, which are composed of phospholipids and a surrounding amphipathic helical protein belt which named membrane scaffold protein (MSP). MSPs provide two surfaces, one is a hydrophilic at the outside, while the other is facing the lipids.
Amphipols is a new class of surfactants, they were synthesized by forming amide bonds between octylamine and, somewhile sopropylamine. Amphipols may be typically used in biophysics and biochemistry by the physicochemical properties of amphipols cut, which is based on the wide resources of polymer chemistry.
SMALPs are disc-like structures containing a protein in a lipid bilayer, the use of styrene maleic acid copolymer (SMA) can make the membrane proteins retention and segregate in the inartificial lipid environment. This molecule cuts discs from the cell membrane of nearly 11 nm in diameter. There are masses of obvious advantages by using SMALPs for structure determination.
These novel detergent-free approaches for saposin production can be obtained easily, and enabling more comprehensively structural and functional studies.
Creative Biostructure provides other various Mempro™ membrane protein production services. Please feel free to contact us for a detailed quote.
References: Rossmann, M., Schultz-Heienbrok, R., Behlke, J., Remmel, N., Alings, C., Sandhoff, K., . . . Maier, T. (2008). Crystal structures of human saposins C and D: implications for lipid recognition and membrane interactions. Structure, 16(5), 809-817.Jamshad, M., Lin, Y.-P., Knowles, T. J., Parslow, R. A., Harris, C., Wheatley, M., Overduin, M. (2011). Surfactant-free purification of membrane proteins with intact native membrane environment. Biochemical Society Transactions, 39(3), 813-818. Yan, N. (2015). Structural biology of the major facilitator superfamily transporters. Annual review of biophysics, 44, 257-283.Rossmann, M., Schultz-Heienbrok, R., Behlke, J., Remmel, N., Alings, C., Sandhoff, K., . . . Maier, T. (2008). Crystal structures of human saposins C and D: implications for lipid recognition and membrane interactions. Structure, 16(5), 809-817.