Hard work, smart research, and Biotinylated PMAL-C8.
That’s how we raise standards.

Amphipols are a class of polymers that are able to stabilize membrane proteins in a detergent-free, aqueous solution(1). The two most common amphipols, Amphipol A8-35 and Amphipol PMAL-C8, have become invaluable tools in the Cryo-EM structure determination of membrane proteins. To further expand their biophysical applications, amphipols can be functionalized with a number of labels, dyes, and tags.
In June 2017, Anatrace launched our Biotinylated Amphipol A8-35 (BAM01), which allows for the immobilization of Amphipol A8-35 reconstituted membrane proteins onto solid supports, including: SPR chips, ELISA plates, and streptavidin coated beads(2). There have been a number of recent publications using Biotinylated A8-35 for a variety of applications:
  • In May 2018, a group at Genentech published a paper in Scientific Reports describing a novel “boost-and-sort” immunization strategy to identify inhibitory antibodies of the E. coli outer membrane protein BamA(3). This method relies on biotinylating the BamA protein in order to perform ELISA or antigen-based sorting.
  • In June 2019, the Genentech group also utilized this same “boost-and-sort” strategy to construct a library of monoclonal antibodies to the E. coli outer membrane protein, LptD, which was published in eLife(4). These antibodies were used to assess the roles of the extracellular loops in LptD, and show that only the loops inaccessible to antibodies were required for the function of this protein.
  • In February 2019, a group at CNRS in France utilized Biotinylated A8-35 to identify the transmembrane domains of membrane proteins using negative stain EM(5). In this study, two model membrane proteins reconstituted in Biotinylated A8-35 are labeled with monovalent streptavidin. These streptavidin labels can be visualized in both the 2D class averages and 3D reconstructions, allowing for the identification of the transmembrane regions of the proteins.

Announcing the launch of Biotinylated PMAL-C8

As we described in our July 2018 Newsletter, the use of Amphipol PMAL-C8 for Cryo-EM continues to increase, with over 10 structures determined in the past three years. Some recent structures determined in 2019 include the Human TRPV3 channel determined by Seok-Yong Lee, Mario Borgnia, and Gabriel Lander at Duke University, NIEHS, and Scripps(6)(7), the Human ClC-1 chloride channel determined by Z. Hong Zhou and Pontus Gourdon at UCLA and the University of Copenhagen(8), and the H. Pylori urea channel determined by Z. Hong Zhou and Keith Munson at UCLA(9).

Due to the increasing use of Amphipol PMAL-C8 for the biochemical and structural studies of membrane proteins, we are excited to launch our Biotinylated PMAL-C8 (BP5008). Similar to the Biotinylated A8-35, this molecule allows for the immobilization of PMAL-C8 reconstituted membrane proteins onto solid supports such as SPR chips, ELISA plates, and streptavidin beads.

Check out the product page for the new Biotinylated PMAL-C8 by clicking here!

  1. Tribet, C., et al. (1996) Proc Natl Acad Sci U S A 93(26), 15047-15050.
  2. Charvolin, D., et al. (2009) Proc Natl Acad Sci U S A, 106(2), 405-410.
  3. Vij, R., et al. (2018) Sci Rep, 8:7136, doi: 10.1038/s41598-018-25609-z.
  4. Storek, K.M., et al. (2019) eLife, 8:e46258, doi: 10.7554/eLife.46258.
  5. Perry, T.N., et al. (2019) Biochim Biophys Acta Biomembr, 1861(2), 466-477
  6. Zubcevic, L., et al. (2019) eLife, 8:e47746, doi: 10.7554/eLife.47746.
  7. Zubcevic, L., et al. (2018) Nat Commun, 9(1), 4773
  8. Wang, K. et al. (2019) PLoS Biol, 17(4):e3000218, doi: 10.1371/journal.pbio.3000218
  9. Cui, Y. et al. (2019) Sci Adv, 5(3):eaav8423, doi: 10.1126/sciadv.aav8423