A novel microseeding method for the crystallization of membrane proteins in lipidic cubic phase.

Autor: Kolek SA; Douglas Instruments Ltd, East Garston, Hungerford RG17 7HD, England., Bräuning B; Department of Chemistry, Technische Universität München, Lichtenbergstrasse 4, 85748 Garching, Germany., Stewart PD; Douglas Instruments Ltd, East Garston, Hungerford RG17 7HD, England.
Jazyk: angličtina
Zdroj: Acta crystallographica. Section F, Structural biology communications [Acta Crystallogr F Struct Biol Commun] 2016 Apr; Vol. 72 (Pt 4), pp. 307-12. Date of Electronic Publication: 2016 Mar 24.
DOI: 10.1107/S2053230X16004118
Abstrakt: Random microseed matrix screening (rMMS), in which seed crystals are added to random crystallization screens, is an important breakthrough in soluble protein crystallization that increases the number of crystallization hits that are available for optimization. This greatly increases the number of soluble protein structures generated every year by typical structural biology laboratories. Inspired by this success, rMMS has been adapted to the crystallization of membrane proteins, making LCP seed stock by scaling up LCP crystallization conditions without changing the physical and chemical parameters that are critical for crystallization. Seed crystals are grown directly in LCP and, as with conventional rMMS, a seeding experiment is combined with an additive experiment. The new method was used with the bacterial integral membrane protein OmpF, and it was found that it increased the number of crystallization hits by almost an order of magnitude: without microseeding one new hit was found, whereas with LCP-rMMS eight new hits were found. It is anticipated that this new method will lead to better diffracting crystals of membrane proteins. A method of generating seed gradients, which allows the LCP seed stock to be diluted and the number of crystals in each LCP bolus to be reduced, if required for optimization, is also demonstrated.
Databáze: MEDLINE