Abstract
A new technique for promoting nucleation and growth of membrane protein (MP) crystals from micellar environments is reported. It relies on the conjugation of micelles that sequester MPs in protein detergent complexes (PDCs). Conjugation via amphiphilic [metal:chelator] complexes presumably takes place at the micelle/water interface, thereby bringing the PDCs into proximity, promoting crystal nucleation and growth. We have successfully applied this approach to two light-driven proton pumps: bacteriorhodopsin (bR) and the recently discovered King Sejong 1-2 (KS1-2), using the amphiphilic 4,4 ' -dinonyl-2,2 ' -dipyridyl (Dinonyl) (0.7 mM) chelator in combination with Zn2+, Fe2+, or Ni2+ (0.1 mM). Crystal growth in the presence of the [metal-chelator] complexes leads to purple, hexagonal crystals (50-75 mu m in size) of bR or pink, rectangular/square crystals (5-15 mu m) of KS1-2. The effects of divalent cation identity and concentration, chelator structure and concentration, ionic strength and pH on crystal size, morphology and process kinetics, are described.
| Original language | English |
|---|---|
| Article number | 12199 |
| Number of pages | 9 |
| Journal | Scientific Reports |
| Volume | 10 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published Online - 22 Jul 2020 |
Funding
We thank the Kimmelman Center for Biomolecular Structure and Assembly and the Benoziyo Endowment Fund for the Advancement of Science for their generous support of M.S. M.S. holds the Katzir Makineni Chair in Chemistry. G.P. thanks Dr. Orly Dym for helpful discussions and the research authority of Ariel University for their generous support. Contributions - T.V.T performed crystallization trials. M.G. expressed KS1–2. N.F. preparation of bR. J.K.H. isolated and prepared the KS1–2 gene. E.W., M.S. and G.P analyzed and discussed the data.
All Science Journal Classification (ASJC) codes
- General