Fluorometric Detection of Enzyme Activity with Synthetic Supramolecular Pores

Das, Gopal; Talukdar, Pinaki; Matile, Stefan

doi:10.1126/science.1077353

Cited by 169 publications

(176 citation statements)

References 16 publications

Supporting

Mentioning

174

Contrasting

Unclassified

Order By: Relevance

“…An early example was Ghadiri's cyclic D/L-peptides, which self-assembled into transmembrane pores large enough for glucose and glutamic acid to pass through. 23,24 In recent years, the β-barrel pores constructed from oligo(phenylene) derivatives by Matile and coworkers 25À27 proved particularly versatile and useful in many applications including sensing 26 and catalysis. 27 Other examples include the porphyrin-based nanopores by Satake and Kobuke, 28 Gong's π-stacked aromatic heterocycles, 29 the metal-coordinated nanopores by Fyles, 30 and the guanosine quartet-based giant ion channels by Davis.…”

Section: ' Introductionmentioning

confidence: 99%

Translocation of Hydrophilic Molecules across Lipid Bilayers by Salt-Bridged Oligocholates

Cho

Zhao

2011

Langmuir

View full text Add to dashboard Cite

Macrocyclic oligocholates were found in a previous work (Cho, H.; Widanapathirana, L.; Zhao, Y. J. Am. Chem. Soc.2011, 133, 141−147) to stack on top of one another in lipid membranes to form nanopores. Pore formation was driven by a strong tendency of the water molecules in the interior of the amphiphilic macrocycles to aggregate in a nonpolar environment. In this work, cholate oligomers terminated with guanidinium and carboxylate groups were found to cause efflux of hydrophilic molecules such as glucose, maltotriose, and carboxyfluorescein (CF) from POPC/POPG liposomes. The cholate trimer outperformed other oligomers in the transport. Lipid-mixing assays and dynamic light scattering ruled out fusion as the cause of leakage. The strong dependence on chain length argues against random intermolecular aggregates as the active transporters. The efflux of glucose triggered by these compounds increased significantly when the bilayers contained 30 mol % cholesterol. Hill analysis suggested that the active transporter consisted of four molecules. The oligocholates were proposed to fold into "noncovalent macrocycles" by the guanidinium−carboxylate salt bridge and stack on top of one another to form similar transmembrane pores as their covalent counterparts. Disciplines Chemistry CommentsReprinted ( Synthetic transmembrane pores with an inner diameter of 1 nm or larger have attracted a great deal of attention in recent years. 1,2 Part of the motivation comes from the fact that their biological congeners, membrane-associated pore-forming proteins, are involved in critical functions such as signaling, metabolism, and bacterial or viral infection. 3À7 Since it is notoriously difficult to obtain detailed structural information for complex membrane proteins, chemists have sought to construct simpler biomimetic nanopores and study their behavior under more easily controlled conditions. Knowledge generated from such studies not only is useful to the understanding of biological pore formation but also helps create materials with potential applications ranging from single-molecule detection of DNAs and RNAs 8À14 to drug delivery. 15 Crown ethers and open chain compounds, which worked extremely well for ion channels, 16À21 normally are too flexible for nanopore formation. To keep the pore open, the structure must be able to withstand the external membrane pressure when incorporated into a bilayer. 22 Despite the significant efforts devoted to synthetic nanopores, limited designs exist currently. An early example was Ghadiri's cyclic D/L-peptides, which self-assembled into transmembrane pores large enough for glucose and glutamic acid to pass through. 23,24 In recent years, the β-barrel pores constructed from oligo(phenylene) derivatives by Matile and coworkers 25À27 proved particularly versatile and useful in many applications including sensing 26 and catalysis. 27 Other examples include the porphyrin-based nanopores by Satake and Kobuke, 28 Gong's π-stacked aromatic heterocycles, 29 the metal-coordinated nanopores by Fy...

show abstract

Section: ' Introductionmentioning

confidence: 99%

Translocation of Hydrophilic Molecules across Lipid Bilayers by Salt-Bridged Oligocholates

Cho

Zhao

2011

Langmuir

View full text Add to dashboard Cite

show abstract

“…On the other hand, dynamic helical assemblies, with stimuli-responsive chiroptical and conformational responses have been used as enantioselective sensors and actuators [34][35][36][37][38] . Another advantage, which can be envisaged of dynamic helical assembly, is their real-time chiroptical readout in response to various processes and stimuli influencing the assembly 39 .…”

mentioning

confidence: 99%

A dynamic supramolecular polymer with stimuli-responsive handedness for in situ probing of enzymatic ATP hydrolysis

et al. 2014

View full text Add to dashboard Cite

Design of artificial systems, which can respond to fluctuations in concentration of adenosine phosphates (APs), can be useful in understanding various biological processes. Helical assemblies of chromophores, which dynamically respond to such changes, can provide realtime chiroptical readout of various chemical transformations. Towards this concept, here we present a supramolecular helix of achiral chromophores, which shows chiral APs responsive tunable handedness along with dynamically switchable helicity. This system, composing of naphthalenediimides with phosphate recognition unit, shows opposite handedness on binding with ATP compared with ADP or AMP, which is comprehensively analysed with molecular dynamic simulations. Such differential signalling along with stimuli-dependent fast stereomutations have been capitalized to probe the reaction kinetics of enzymatic ATP hydrolysis. Detailed chiroptical analyses provide mechanistic insights into the enzymatic hydrolysis and various intermediate steps. Thus, a unique dynamic helical assembly to monitor the real-time reaction processes via its stimuli-responsive chiroptical signalling is conceptualized.

show abstract

“…13 Without careful consideration of the ion selectivity of both pore and assay, this could have been the end of a project, leaving much excitement with the marvelous multifunctionality of this pore undiscovered because of a careless interpretation. 1,[11][12][13][14] Conductance measurements in BLMs confirmed that the cation selectivity of pore 6 was as high as expected for an inner surface covered with carboxylates (P K þ =P Cl À ¼ 5:6). 15 This high permeability ratio may also serve as instructive example to correct the frequent misconception that the large inner diameter of pores is incompatible with anion/ cation selectivity: It is the chemical nature rather than the size of the pore that matters, absence of anion/cation selectivity does not identify pores (and vice versa).…”

Section: Determination Of the Anion/cation Selectivity Of Synthetic Pmentioning

confidence: 72%

The determination of the ion selectivity of synthetic ion channels and pores in vesicles

Sakai

Matile

2006

J of Physical Organic Chem

Self Cite

View full text Add to dashboard Cite

Organic chemists entering the field of synthetic ion channels and pores are often restricted to the characterization of their creation by fluorescence kinetics in vesicles and do not have access to conductance experiments in planar bilayer membranes. This limitation excludes the application of methods to evaluate key characteristics such as ion selectivity or voltage gating that are routine in the membrane biophysics community.

show abstract

Fluorometric Detection of Enzyme Activity with Synthetic Supramolecular Pores

Cited by 169 publications

References 16 publications

Translocation of Hydrophilic Molecules across Lipid Bilayers by Salt-Bridged Oligocholates

Translocation of Hydrophilic Molecules across Lipid Bilayers by Salt-Bridged Oligocholates

A dynamic supramolecular polymer with stimuli-responsive handedness for in situ probing of enzymatic ATP hydrolysis

The determination of the ion selectivity of synthetic ion channels and pores in vesicles

Contact Info

Product

Resources

About