Self‐Assembly Behaviors of a Penta‐Phenylene Maltoside and Its Application for Membrane Protein Study

Abstract

We prepared an amphiphile with ap enta-phenylene lipophilic group and ab ranched trimaltoside head group. This new agent, designated penta-phenylene maltoside (PPM), showedamarked tendency to self-assembly into micelles via strong aromatic-aromatic interactions in aqueous media, as evidenced by 1 HNMR spectroscopy and fluorescences tudies. When utilized for membrane protein studies, this new agentw as superior to DDM, a gold standard conventionald etergent, in stabilizing multiple proteins long term. The ability of this agent to form aromatic-aromatic interactions is likely responsible for enhanced protein stabilization when associated with at arget membranep rotein.Self-assembly,ageneral phenomenon in nature, plays ap ivotal role in various biological functions. [1] Inspired by the abundance of self-assembly processes in biological systems, considerable efforts have been devoted to the design and synthesis [a] M.The authors declare the following competing financial interest(s):P .S.C. and M.E. are inventors on ap atenta pplicationt hat coverst he PPM agent

Maltose-bis(hydroxymethyl)phenol (MBPs) and Maltose-tris(hydroxymethyl)phenol (MTPs) Amphiphiles for Membrane Protein Stability

“…As the new detergents contain an aromatic group (i.e., benzene) between the head and tail groups, they have potential to form aromatic–aromatic interactions between detergent molecules in a self-assembly environment. In order to investigate this possibility, 1 H NMR spectra of MBP-C8 were measured in D 2 O. , When dissolved in CD 3 OD at 25 °C, MBP-C8 produced two well-resolved signals at 7.05 and 6.92 ppm, corresponding to the aromatic protons of H b and H c (Figure a). When D 2 O was used as an NMR solvent, all signals were significantly broadened due to the self-assembly formation in an aqueous environment.…”

“…In order to investigate this possibility, 1 H NMR spectra of MBP-C8 were measured in D 2 O. 56,60 When dissolved in CD 3 OD at 25 °C, MBP-C8 produced two well-resolved signals at 7.05 and 6.92 ppm, corresponding to the aromatic protons of H b and H c (Figure 2a). When D 2 O was used as an NMR solvent, all signals were significantly broadened due to the self-assembly formation in an aqueous environment.…”

“…Among these detergents, the two NG class amphiphiles, MNG-3 and GNG-3 (as known as LMNG and OGNG, respectively), are particularly interesting as these novel detergents have contributed to the determination of more than 40 new membrane protein structures including several G protein-coupled receptors (GPCRs) over the past decade. − This contribution has encouraged chemists to further develop innovative amphiphiles to facilitate membrane protein structural study. Recent examples include glyco-tripod amphiphiles (TPAs), fluorinated detergents, mannitol/mesitylene-based glucoside amphiphiles (MNAs/MGAs), , rigid core-bearing amphiphiles ((norbornane (NBMs)/resorcinarene (RGAs)/scylloinositol (SIGs)/1,3,5-triazine (TEMs)), − and rigid hydrophobic group-bearing amphiphiles (e.g., glyco-diosgenin (GDN) and penta-phenylene maltoside (PPM)). , Notably, some recent inventions such as penta-saccharide-bearing amphiphiles (PSEs), dendronic trimaltosides (DTMs), vitamin E-based glucosides (VEGs), and terphenyl-cored trimaltosides (TPMs) produced very high quality EM micrographs of the human β 2 -adrenergic receptor (β 2 AR)-G protein complex. − We recently reported asymmetric MNGs (A-MNGs) and pendant-bearing GNGs (P-GNGs) that are significantly more effective than the original amphiphiles (LMNG and OGNG, respectively) at stabilizing membrane proteins, highlighting the possibility to further improve detergent properties via structural modifications. , As part of our long-term efforts, here we describe two sets of aromatic ring-based maltosides, maltose-bis­(hydroxymethyl)­phenol (MBPs) and maltose-tris­(hydroxymethyl)­phenol (MTPs), designated according to the linkers used to connect the head and tail groups. Evaluation of these detergents with several model membrane protein systems revealed that a couple of the new agents conferred enhanced stability to all tested membrane proteins including two GPCRs compared to a gold standard detergent (DDM).…”

“…Recent examples include glyco-tripod amphiphiles (TPAs), 47 fluorinated detergents, 48 mannitol/mesitylene-based glucoside amphiphiles (MNAs/ MGAs), 49,50 rigid core-bearing amphiphiles ((norbornane (NBMs)/resorcinarene (RGAs)/scylloinositol (SIGs)/1,3,5triazine (TEMs)), 51−54 and rigid hydrophobic group-bearing amphiphiles (e.g., glyco-diosgenin (GDN) and penta-phenylene maltoside (PPM)). 55,56 Notably, some recent inventions such as penta-saccharide-bearing amphiphiles (PSEs), dendronic trimaltosides (DTMs), vitamin E-based glucosides (VEGs), and terphenyl-cored trimaltosides (TPMs) produced very high quality EM micrographs of the human β 2 -adrenergic receptor (β 2 AR)-G protein complex. 57−60 We recently reported asymmetric MNGs (A-MNGs) and pendant-bearing GNGs (P-GNGs) that are significantly more effective than the original amphiphiles (LMNG and OGNG, respectively) at stabilizing membrane proteins, highlighting the possibility to further improve detergent properties via structural modifications.…”

New Malonate-Derived Tetraglucoside Detergents for Membrane Protein Stability

“…Our group and others have made substantial efforts to develop novel classes of detergents with enhanced protein stabilization efficacy. Representatives include glyco-tripod amphiphiles (TPAs), , hemifluorinated surfactants (HFSs), , cholate or deoxycholate-based facial amphiphiles (FAs), , neopentyl glycol-based amphiphiles (GNGs/MNGs/NDTs), − mannitol-based or mesitylene-linked glucoside amphiphiles (MNAs and MGAs), , rigid core (norbornane/resorcinarene/terphenyl/1,3,5-triazine)-bearing amphiphiles (NBMs/RGAs/TPMs/TEMs), − and rigid hydrophobic group-bearing amphiphiles (e.g., chobimalt, glyco-diosgenin (GDN), and penta-phenylene maltoside (PPM)). Notably, some recent inventions such as penta-saccharide-bearing amphiphiles (PSEs), dendronic trimaltosides (DTMs), and vitamin E-based glucosides (VEGs) showed favorable behaviors for visualization of human β 2 -adrenergic receptor (β 2 AR) via EM analysis.…”