The Journal of Membrane Biology

, Volume 247, Issue 9, pp 759–796

Amphipols for Each Season

Article

DOI: 10.1007/s00232-014-9666-8

Cite this article as:
Zoonens, M. & Popot, JL. J Membrane Biol (2014) 247: 759. doi:10.1007/s00232-014-9666-8

Abstract

Amphipols (APols) are short amphipathic polymers that can substitute for detergents at the transmembrane surface of membrane proteins (MPs) and, thereby, keep them soluble in detergent free aqueous solutions. APol-trapped MPs are, as a rule, more stable biochemically than their detergent-solubilized counterparts. APols have proven useful to produce MPs, most noticeably by assisting their folding from the denatured state obtained after solubilizing MP inclusion bodies in either SDS or urea. They facilitate the handling in aqueous solution of fragile MPs for the purpose of proteomics, structural and functional studies, and therapeutics. Because APols can be chemically labeled or functionalized, and they form very stable complexes with MPs, they can also be used to functionalize those indirectly, which opens onto many novel applications. Following a brief recall of the properties of APols and MP/APol complexes, an update is provided of recent progress in these various fields.

Keywords

Membrane proteins Surfactants Stabilization Folding Biochemistry Biophysics 

Abbreviations

2D

Two-dimensional

3D

Three-dimensional

A8-35

A poly(sodium acrylate) based amphipol comprising ~35 % of free carboxylates, ~25 % of octyl chains, ~40 % of isopropyl groups, whose number average molar mass is ~4.3 kDa

A8-75

A poly(sodium acrylate) based amphipol comprising ~75 % of free carboxylates, ~25 % of octyl chains, whose number average molar mass is ~4 kDa

APol

Amphipol

AUC

Analytical ultracentrifugation

BAPol

Biotinylated A8-35

BLM

Black lipid membrane

BN-PAGE

Blue native polyacrylamide gel electrophoresis

BR

Bacteriorhodopsin

CAC

Critical aggregation concentration

CD

Circular dichroism

Đ

Polydispersity index

cmc

Critical micellar concentration

DAGK

Diacylglycerol kinase

DAPol

A8-35 with deuterated octylamine and isopropylamine side chains

DHPC

Dihexanoylphosphatidylcholine

DLS

Dynamic light scattering

DPC

Dodecylphosphocholine

DPn

See 〈Xn

EM

Electron microscopy

EPR

Electron paramagnetic resonance

ESI

Electron spray ionization

FAPol

Fluorescently-labeled A8-35

FAPolAF647

Alexa Fluor 647-labeled A8-35

FAPolNBD

Nitrobenzoxadiazole-labeled A8-35

FAPolrhod

Rhodamine-labeled A8-35

FRET

Förster resonance energy transfer

GFP

Green fluorescent protein

GPCR

G protein-coupled receptor

HAPol

Hydrogenated A8-35

His6PEG

N-(Penta(histidyl)histidinamide)-8-amino-3,6-dioxa-octanamide

His-tag

Hexahistidine tag

HistAPol

Hexahistidine tag-carrying A8-35

IMAC

Immobilized metal ion affinity chromatography

ImidAPol

Imidazole-carrying A8-35

IMS

Ion mobility spectrometry

INS

Inelastic neutron scattering

ITC

Isothermal titration calorimetry

KpOmpA

The transmembrane domain of outer membrane protein A from Klebsiella pneumoniae

LTB4

Leukotriene B4

Mn〉 (also written \( \bar{M}_{\text{n}} \))

Number-average molar mass

MALDI

Matrix-assisted laser desorption ionization

MOMP

The major outer membrane protein from Chlamydia trachomatis

MP

Membrane protein

MS

Mass spectrometry

MW

Molecular weight

nAChR

Nicotinic acetylcholine receptor

NAPol

Non-ionic APol

NBD

7-Nitrobenz-2-oxa-1,3-diazol-4-yle

ND

Nanodisc

NOE

Nuclear Overhauser effect

NTA

Nitrilotriacetic acid

ODN

Oligodeoxynucleotide

OligAPol

ODN-carrying A8-35

OmpA, OmpF, OmpX

Respectively outer membrane proteins A, F and X from Escherichia coli

PAA

Poly(acrylic acid)

PAGE

Polyacrylamide gel electrophoresis

PC-APol

Phosphorylcholine-based APol

perDAPol

Perdeuterated A8-35

QENS

Quasi-elastic neutron scattering

SANS

Small angle neutron scattering

SAPol

Sulfonated amphipol derived from A8-75, comprising ~40 % of taurine moieties

SAXS

Small angle X-ray scattering

SDS

Sodium dodecyl sulfate

SERCA1a

The sarcoplasmic calcium ATPase from twitch muscle

SERS

Surface-enhanced Raman scattering

SMFS

Single-molecule force spectrometry

SPR

Surface plasmon resonance

SR

Synchrotron radiation

STEM

Scanning transmission EM

Structure II

Secondary structure

SulfidAPol

Sulfide-carrying APol

TOF

Time of flight

tOmpA

The transmembrane domain of OmpA from E. coli

TRP

Transient receptor potential

UAPol

Universal amphipol

UAPol-NH2

Amine-carrying A8-35

Xn〉 (also written \( \bar{X}_{\text{n}} \), formerly DPn)

Number-average degree of polymerization

Copyright information

© Springer Science+Business Media New York 2014

Authors and Affiliations

  1. 1.Laboratoire de Physico-Chimie Moléculaire des Protéines MembranairesUMR 7099, Institut de Biologie Physico-Chimique (FRC 550), Centre National de la Recherche Scientifique/Université Paris-7ParisFrance