Making dimers of oligomeric membrane proteins using copper-free click chemistry

Wang Dong,James N Sturgis

doi:10.12688/f1000research.8676.1

Abstract

Here we describe the development of a protocol to make small oligomers, dimers and trimers, from highly oligomeric membrane proteins. The proteins that we used are the light harvesting 2 proteins and core complexes from photosynthetic bacteria, which contain respectively 16 and 56 individual polypeptides. Creating specific dimers between such multimeric protein poses several problems. We propose a protocol based on asymmetric lysine localization, thanks to the positive inside rule, and copper-free click chemistry. With this method we are able to produce specific dimeric complexes in detergent solution of possible biological relevance.

Highlights

The light harvesting apparatus of photosynthetic bacteria, and of all photosynthetic organisms, is organized in a large array of complex structure
In most purple bacteria the light collection array is comprised of two proteins: the reaction center containing core complex (CC), and the peripheral light harvesting complex (LH2)
The visible proteins are of two types: smaller rings composed of light harvesting 2 (LH2), a molecular model of which is shown in panel B, and larger rings composed of CC, a molecular model of which is shown in panel C

Summary

Introduction

The light harvesting apparatus of photosynthetic bacteria, and of all photosynthetic organisms, is organized in a large array of complex structure. This array is designed to absorb light energy and efficiently funnel it to available reaction centers[1]. In most purple bacteria the light collection array is comprised of two proteins: the reaction center containing core complex (CC), and the peripheral light harvesting complex (LH2). Analysis of the organization of these proteins[2] has shown that this organization can be described as a mixture of hexagonal packed arrays of the nonameric LH2, and a more randomly organized LH2 CC mixture

Methods

Results

Conclusion