Pil Seok Chae

• Hanyang University

Mixed nano‐assemblies formed by two surfactants have rarely been used to catalyze organic reactions. In this study, nano‐assemblies formed by SDS and CTAB were applied for the etherification of allylic alcohols with benzyl, aliphatic, and natural product alcohols at room temperature in an aqueous medium. In the presence of SDS‐CTAB nano‐assemblies...

Membrane proteins play a crucial role in a variety of biological processes and are key targets for pharmaceutical development. Structural studies of membrane proteins provide molecular insights into the mechanisms of these processes and are essential for effective drug discovery. Historically, these studies have relied on solubilization of the targ...

Copper metal ions (Cu2+) are widely used in various industries, and their salts are used as supplementary components in agriculture and medicine. As this metal ion is associated with various health issues, it is necessary to detect and monitor it in environmental and biological samples. In the present report, we synthesized a naphthoquinoline-dione...

Development of a fluorescent probe with an ability to detect two different analytes is challenging. Implanting two distinct properties into a single molecule is necessary to attain this dual-responsiveness. In the current study, we prepared two phenothiazine-based probes (probes 1 and 2) with the abilities to detect both moisture in organic solvent...

Nano-assemblies such as surfactant micelles and vesicles are widely used in drug carriers, bioreactors, and gene delivery but can also be used as catalytic systems for chemical transformations. In the...

Membrane proteins are bio-macromolecules that constitute ∼60% of current drug targets. Over the past decade, we have witnessed a number of technological advancements, techniques, and reagents for membrane protein structural biology, resulting in an ever-growing number of membrane proteins with known structures. Before being analyzed by structural,...

Membrane proteins serve essential roles in a number of biological processes, and their structures are important in elucidating such processes at the molecular level and also for rational drug design and development. Membrane protein structure determination is notoriously challenging compared to that of soluble proteins, due largely to the inherent...

The present invention relates to: amphipathic compounds derived from 1,3-acetonedicarboxylate; a preparation method therefor; and a method for extracting, solubilizing, stabilizing, crystallizing or analyzing membrane proteins by using the same. In addition, the compound enables membrane proteins, which have various structures and characteristics,...

The widespread use of cyanide (CN−) in industry results in contamination of various effluents such as drain, lake, and tap water, an imminent danger to the environment and human health. We prepared naphthoquinolinedione (cyclized; 1–5) and anthracenedione (un-cyclized) probes (6–7) for selective detection of CN−. The addition of CN− to the probe so...

The widespread use of cyanide (CN-) in industry results in contamination of various effluents such as drain, lake, and tap water, an imminent danger to the environment and human health. We prepared naphthoquinolinedione (cyclized; 1-5) and anthracenedione (un-cyclized) probes (6-7) for selective detection of CN-. The addition of CN- to the probe so...

High-resolution membrane protein structures are essential for a fundamental understanding of the molecular basis of diverse cellular processes and for drug discovery. Detergents are widely used to extract membrane-spanning proteins from membranes and maintain them in a functional state for downstream characterization. Due to limited long-term stabi...

We report the synthesis and characterization of a new family of maltose-derived nonionic surfactants that contain a photocleavable azo-sulfide linker (mAzo). The self-assembly properties of these surfactants were investigated using surface tension measurements to determine the critical micelle concentration (CMC), dynamic light scattering (DLS) to...

Though sulfonamides are biologically important molecules, the scope of their structures is narrow due to the limited methods available for synthesis. Alkene functionalization has recently gained attention for synthesis of...

Detergents have been major contributors to membrane‐protein structural study for decades. However, membrane proteins solubilized in conventional detergents tend to aggregate or denature over time. Stability of large eukaryotic membrane proteins with complex structures tends to be particularly poor, necessitating development of novel detergents with...

Detergents are widely used for membrane protein structural study. Many recently developed detergents contain multiple tail and head groups, which are typically connected via a small and branched linker. Due to their inherent compact structures, with small inter‐alkyl chain distances, these detergents form micelles with high alkyl chain density in t...

Wide usage of Cu2+ and F− in various industries and their potential hazard toward human health necessitate the development of a probe for their selective and sensitive detection. While various probes have been invented for the respective detection of these two ions, there are few probes allowing for their simultaneous or sequential detection. The c...

Wide usage of Cu²⁺ and F⁻ in various industries and their potential hazard toward human health necessitate the development of a probe for their selective and sensitive detection. While various probes have been invented for the respective detection of these two ions, there are few probes allowing for their simultaneous or sequential detection. The c...

Detergents are extensively used for membrane protein manipulation. Membrane proteins solubilized in conventional detergents are prone to denaturation and aggregation, rendering downstream characterization of these bio-macromolecules difficult. Although many amphiphiles have been developed to overcome the limited efficacy of conventional detergents...

Membrane proteins are of biological and pharmaceutical significance. However, their structural study is extremely challenging mainly due to the fact that only a small number of chemical tools are suitable for stabilizing membrane proteins in solution. Detergents are widely used in membrane protein study, but conventional detergents are generally po...

Detergents are widely used for membrane protein solubilization, purification, and structural analysis. Over the past two decades, much effort has been made to design novel detergents with improved properties. Here, we provide the details of 23 different classes of novel detergents with particular focus on OGNG, LMNG, and GDN, which have been widely...

Integral membrane proteins pose considerable challenges to high resolution structural analysis. Maintaining membrane proteins in their native state during protein isolation is essential for structural study of these bio‐macromolecules. Detergents are the most commonly used amphiphilic compounds for stabilizing membrane proteins in solution outside...

The presence of an abnormal amount of Cu2+ in the human body causes various health issues. In the current study, we synthesized a new naphthoquinolinedione-based probe (probe 1) to monitor Cu2+ in different water systems, such as tap water, lakes, and drain water. Two triazole units were introduced into the probe via a click reaction to increase th...

The presence of an abnormal amount of Cu2+ in the human body causes various health issues. In the current study, we synthesized a new naphthoquinolinedione-based probe (probe 1) to monitor Cu2+ in different water systems, such as tap water, lakes, and drain water. Two triazole units were introduced into the probe via a click reaction to increase th...

Mercury ions are an industrial and environmental toxin that need to be monitored and regulated in aqueous samples. We prepared six probes (1–6) using a naphthoquinolinedione ring as a fluorophore platform that contains different substituents on the quinolone ring. All probes showed abilities to selectively bind Hg2+, but their sensitivity to the de...

Mercury ions are an industrial and environmental toxin that need to be monitored and regulated in aqueous samples. We prepared six probes (1–6) using a naphthoquinolinedione ring as a fluorophore platform that contains different substituents on the quinolone ring. All probes showed abilities to selectively bind Hg²⁺, but their sensitivity to the de...

Membrane protein structures provide atomic level insight into essential biochemical processes and facilitate protein structure-based drug design. However, the inherent instability of these bio-macromolecules outside lipid bilayers hampers their structural and functional study. Detergent micelles can be used to solubilize and stabilize these membran...

Dimethyl sulfoxide (DMSO) and dimethylformamide (DMF) are industrial toxins that need to be sensed. We synthesized 1,8-naphthalimide-m-benzenesulfonamide (NBS)-bearing probes (1–5) with different pendant chains for sensitive detection of DMSO and DMF. These probes exhibited aggregation-induced emission enhancement with increasing water concentratio...

Dimethylsulfoxide (DMSO) and dimethylformamide (DMF) are industrial toxins that need to be sensed. We synthesized 1,8-naphthalimide-m-benzenesulfonamide (NBS)-bearing probes (1–5) with different pendant chains for sensitive detection of DMSO and DMF. These probes exhibited aggregation-induced emission enhancement with increasing water concentration...

Amphiphilic agents, called detergents, are invaluable tools for studying membrane proteins. However, membrane proteins encapsulated by conventional head-to-tail detergents tend to denature or aggregate, necessitating the development of structurally distinct molecules with improved efficacy. Here, a novel class of diastereomeric detergents with a cy...

The present invention relates to a newly developed steroid-based amphiphilic compound, a method for preparing the same, and a method for extracting, dissolving, stabilizing, crystallizing or analyzing a membrane protein using the same. In addition, this compound can efficiently extract membrane proteins with a variety of structures and properties t...

The present invention relates to a vitamin E-based amphipathic compound, a method for producing same, and a method for extracting, solubilizing, stabilizing, or crystallizing a membrane protein using same. By using a compound according to the present invention, not only is an excellent membrane protein extraction and solubilization effect achieved,...

Membrane proteins are widely studied in detergent micelles, a membrane-mimetic system formed by amphiphilic compounds. However, classical detergents have serious limitations in their utility, particularly for unstable proteins such as eukaryotic membrane proteins and membrane protein complexes, and thus, there is an unmet need for novel amphiphiles...

Glucoside detergents are successfully used for membrane protein crystallization mainly because of their ability to form small protein-detergent complexes. In a previous study, we introduced glucose neopentyl glycol (GNG) amphiphiles with a branched diglucoside structure that has facilitated high resolution crystallographic structure determination o...

A newly synthesized anthrapyridone-based diamine (probe 1) having two metal ion binding sites exhibited selective and sensitive sensing of Cu2þ or Hg2þ among various metal ions. Upon addition of the metal ion, the probe 1-containing solution vividly changed color, enabling visual detection of each metal ion (Cu2þ or Hg2þ) without requiring any inst...

The present invention relates to a newly developed terphenyl-based amphiphile compound, a method for manufacturing the same, and a method for extracting, solubilizing, stabilizing, crystalizing, or analyzing a membrane protein using the same. Also, the corresponding compound can efficiently extract membrane proteins having various structures and pr...

A newly synthesized anthrapyridone-based diamine (probe 1) having two metal ion binding sites exhibited selective and sensitive sensing of Cu²⁺ or Hg²⁺ among various metal ions. Upon addition of the metal ion, the probe 1-containing solution vividly changed color, enabling visual detection of each metal ion (Cu²⁺ or Hg²⁺) without requiring any inst...

Human epidermal growth factor receptors (HERs) are the primary targets of many directed cancer therapies. However, the reason a specific dimer of HERs generates a stronger proliferative signal than other permutations remains unclear. Here, we used single-molecule immunoprecipitation to develop a biochemical assay for endogenously-formed, entire HER...

Human epidermal growth factor receptors (HERs) are the primary targets of many directed cancer therapies. However, the reason a specific dimer of HERs generates a stronger proliferative signal than other permutations remains unclear. Here, we used single-molecule immunoprecipitation to develop a biochemical assay for endogenously-formed, entire HER...

Human epidermal growth factor receptors (HERs) are the primary targets of many directed cancer therapies. However, the reason a specific dimer of HERs generates a stronger proliferative signal than other permutations remains unclear. Here, we used single-molecule immunoprecipitation to develop a biochemical assay for endogenously-formed, entire HER...

Cyanide anion (CN−) is one of the most hazardous chemicals for humans but is inevitably used in various purposes. In this study, we prepared fluorescent pyridoanthrone-based probes 1 and 3 with an N-octyl viologen pendant to detect this toxic anion. Among various anions, the presence of CN− only turned over a large fluorescence enhancement of these...

Amphipathic agents are widely used in various fields including biomedical sciences. Micelle‐forming detergents are particularly useful for in vitro membrane‐protein characterization. As many conventional detergents are limited in their ability to stabilize membrane proteins, it is necessary to develop novel detergents to facilitate membrane‐protein...

Detergents are widely used to isolate membrane proteins from lipid bilayers, but many proteins solubilized in conven-tional detergents are structurally unstable. Thus, there is major interest in the development of novel amphiphiles to facili-tate membrane protein research. In the present study, we have designed and synthesized novel amphiphiles wit...

Disclosed are an amphipathic compound having a penta-saccharide hydrophilic group, a method of preparing the same, and a method of extracting, solubilizing, stabilizing, crystallizing or analyzing membrane proteins and membrane protein complexes using the same. In particular, since the compound has a high-density penta-saccharide hydrophilic group...

Correction for ‘Trehalose-cored amphiphiles for membrane protein stabilization: importance of the detergent micelle size in GPCR stability’ by Manabendra Das et al. , Org. Biomol. Chem. , 2019, 17 , 3249–3257.

We prepared an amphiphile with a penta‐phenylene lipophilic group and a branched trimaltoside head group. This new agent, designated penta‐phenylene maltoside (PPM), showed a marked tendency to self‐assembly into micelles via strong aromatic–aromatic interactions in aqueous media, as evidenced by ¹H NMR spectroscopy and fluorescence studies. When u...

Despite their importance in biology and medicinal chemistry, structural and functional studies of membrane proteins present major challenges. To study diverse membrane proteins, it is crucial to have the correct detergent to efficiently extract and stabilize the proteins from the native membranes for biochemical/biophysical downstream analyses. But...

The study of membrane proteins is extremely challenging, mainly because of the incompatibility of the hydrophobic surfaces of membrane proteins with an aqueous medium. Detergents are essential agents used to maintain membrane protein stability in non-native environments. However, conventional detergents fail to stabilize the native structures of ma...

Six thiophene-bis(benzimidazole)-based molecular probes with tunable fluorescence emission were synthesized for selective Hg2+ detection. Probe 1 contains a thiophene-bis(benzimidazole) unit without an appendage, while probes 2-4 have multiple appendages on benzimidazole rings of the core and probe 6/7 has two biphenyl appendages on the thiophene r...

Maintaining protein stability in an aqueous solution is a prerequisite for protein structural and functional studies, but conventional detergents have increasingly showed the limited ability to maintain protein integrity. A representative novel agent, maltose neopentyl glycol-3 (MNG-3), has recently substantially contributed for membrane protein st...

An imidazolium-bearing dansyl-based probe (probe 1; D) and three dicynovinyl group-containing substrates with different alkyl chain length (S1, S2 and S3) were prepared. Three binary ensembles, designated DS1, DS2, and DS3, were generated for CN − detection in a buffer solution of HEPES: DMSO (2:8) (pH = 7.4) by combining these probe and substrates...

The study of membrane proteins is extremely challenging, mainly because of the incompatibility of the hydrophobic surfaces of membrane proteins with an aqueous medium. Detergents are essential agents used to maintain membrane protein stability in non-native environments. However, conventional detergents fail to stabilize the native structures of ma...

Biological membranes contain a variety of membrane proteins that act as receptors, signal transducers, channels, transporters, motors, and anchors. High-resolution structures of membrane proteins are of paramount importance for understanding mechanism of action at a molecular level and are of significant implications for biomedical and pharmaceutic...

Membrane proteins play crucial roles in regulating cellular functions at the interface between cells and their environments or on the surface of organelles. The major bottleneck for their structure study arises from their instability outside the native environments. Amphipathic agents, called detergents, form micelles which mimic the lipid environm...

Amphiphiles are critical tools for membrane protein structural and functional study. Membrane proteins encapsulated by conventional head‐to‐tail detergents tend to undergo structural degradation, necessitating the development of structurally novel agents with improved efficacy. In recent years, facial amphiphiles have yielded encouraging results in...

In this study, we designed and prepared pyrene-based dipodal probes with a range of molecular flexibility for picric acid (PA) detection. These probes commonly contain a central rigid core, but probe 1 contains relatively short linkers/spacers compared to probes 2 and 3. The dipodal probes produced dominant pyrene excimer fluorescence in an aqueous...

In this study, we designed and prepared pyrene-based dipodal probes with a range of molecular flexibility for picric acid (PA) detection. These probes commonly contain a central rigid core, but probe 1 contains relatively short linkers/spacers compared to probes 2 and 3. The dipodal probes produced dominant pyrene excimer fluorescence in an aqueous...

Membrane proteins play critical roles in a variety of cellular processes. For a detailed molecular level understanding of their biological functions and roles in disease, it is necessary to extract them from the native membranes. While the amphipathic nature of these bio-macromolecules presents technical challenges, amphiphilic assistants such as d...

Membrane proteins allow effective communication between cells and organelles and their external environments. Maintaining membrane protein stability in a non‐native environment is the major bottleneck to their structural study. Detergents are widely used to extract membrane proteins from the membrane and keep the extracted protein in a stable state...

Integral membrane proteins either alone or as complexes carry out a range of key cellular functions. Detergents are indispensable tools in the isolation of membrane proteins from biological membranes for downstream studies. Although a large number of techniques and tools, including a wide variety of detergents, are available, purification and struc...

Membrane proteins constitute about a third of the open reading frames in the human genome and are the targets of more than half of current pharmaceuticals. For structural and functional characterizations, membrane proteins generally need to be extracted from the membranes and reconstituted in a suitable membrane-mimicking environment. Detergents ar...

Pyrene-appended dipodal probes (probes 1 and 2) with differences in conformational rigidity were synthesized for sensitive detection of 3,5-dinitrosalicylic acid (DNSA) in an aqueous solution. Both dipodal probes had two pyrene units and exhibited quenching caused by aggregation (ACQ) at high water content (>60%) in DMSO. As the pyrene dimer (e.g.,...

High-resolution membrane protein structures are essential for understanding the molecular basis of diverse biological events and important in drug development. Detergents are usually used to extract these bio-macromolecules from the membranes and maintain them in a soluble and stable state in aqueous solutions for downstream characterization. Howev...

Two 1,8-naphthalimide (NPI)-conjugated sulfonamide probes (1 and 2) were synthesized for sensitive detection of 2,4,6-trinitrophenol (TNP) in aqueous media. In a PBS buffer, probe 1 (with two NPI units) showed an emission spectrum with λmax = 484 nm while probe 2 (with only one NPI unit) gave an emission spectrum with λmax = 383 nm. Probe 1 showed...

As a membrane-mimetic system, detergent micelles are popularly used to extract membrane proteins from the lipid environment and to maintain their solubility and stability in an aqueous medium. Despite the wide utility in membrane protein research, many membrane proteins encapsulated in conventional detergents tend to undergo structural degradation...

Detergents are essential tools for functional and structural studies of membrane proteins. However, conventional detergents are limited in their scope and utility, particularly for eukaryotic membrane proteins. Thus, there are major efforts to develop new amphipathic agents with enhanced properties. Here, a novel class of diastereomeric agents with...

Applied for KR & PCT patent (Aug. 10, 2016; Feb. 10, 2017)

Applied for KR & PCT patent (Jan. 24, 2017; Feb. 10, 2017)

Three electronically tuned fluorescent probes (1–3) were synthesized by conjugating a fluorescent unit to N,N-bis-(hydroxyethyl)ethylenediamine. Probe 1 bearing an electron-deficient naphthalenedimide unit did not give a fluorescence response to the presence of various metal ions including monovalent metal ions (Na⁺, K⁺, and Ag⁺), divalent metal io...

Membrane proteins encapsulated by detergent micelles are widely used for structural study. Because of their amphipathic property, detergents have the ability to maintain protein solubility and stability in an aqueous medium. However, conventional detergents have serious limitations in their scope and utility, particularly for eukaryotic membrane pr...

Membrane proteins are crucial components for a number of cellular functions, but are difficult to study their structure and functions because these bio-macromolecules are generally unstable when removed from their native membranes. A number of new detergents, lipids and non-detergent-like amphiphiles have been developed to stabilize membrane protei...

Amphiphile selection is a crucial step in membrane protein structural and functional study. As conventional detergents have limited scope and utility, novel agents with enhanced efficacy need to be developed. Although a large number of novel agents have been reported, so far there has been no systematically designed comparative study of the protein...

Detergents serve as useful tools for membrane protein structural and functional studies. Their amphipathic nature allows detergents to associate with the hydrophobic regions of membrane proteins whilst maintaining the proteins in aqueous solution. However, widely used conventional detergents have major limitations and thus there are major efforts t...

Amphiphile selection is a crucial step in membrane protein structural and functional study. As conventional detergents have limited scope and utility, novel agents with enhanced efficacy need to be developed. Although a large number of novel agents have been reported, so far there has been no systematically designed comparative study of the protein...

A novel class of detergents, designated tandem neopentyl glycol maltosides (TNMs), were evaluated with four target membrane proteins. The best detergent varied depending on the target, but TNM-C12L and TNM-C11S were notable for their ability to confer increased membrane protein stability compared to DDM. These agents have potential for use in membr...

tTwo 1,8-naphthalimide (NPI)-conjugated sulfonamide probes (1 and 2) were synthesized for sensitivedetection of 2,4,6-trinitrophenol (TNP) in aqueous media. In a PBS buffer, probe 1 (with two NPI units)showed an emission spectrum with �max= 484 nm while probe 2 (with only one NPI unit) gave an emissionspectrum with �max= 383 nm. Probe 1 showed aggr...

Applied for KR & PCT patent (Aug. 10, 2016; Feb. 10, 2017)

The comparative studies on diastereomeric amphiphiles towards membrane protein stabilization were described and the results show that the chirality variation leads to significant differences in membrane protein stabilization.

Integral membrane proteins are amphipathic molecules crucial for all cellular life. The structural study of these macromolecules starts with protein extraction from the native membranes, followed by purification and crystallisation. Detergents are essential tools for these processes, but detergent-solubilised membrane proteins often denature and ag...

Detergents are essential tools for membrane protein manipulation. Micelles formed by detergent molecules have the ability to encapsulate the hydrophobic domains of membrane proteins. The resulting protein-detergent complexes (PDCs) are compatible with the polar environments of aqueous media, making structural and functional analysis feasible. Altho...

Membrane proteins carry out a number of vital functions such as signal transduction, material transfer, cell-cell recognition across lipid barriers and many more. The structure elucidation of these biomolecules enables us to rationally design drug molecules and has thus drawn significant attention in scientific community. However, membrane proteins...

Membrane proteins are amphipathic bio-macromolecules incompatible with the polar environments of aqueous media. Conventional detergents encapsulate the hydrophobic surfaces of membrane proteins allowing them to exist in aqueous solution. Membrane proteins stabilized by detergent micelles are used for structural and functional analysis. Despite the...

The effect of various detergents on the stability and function of the melibiose permeases of Escherichia coli (MelBEc) and Salmonella typhimurium (MelBSt) was studied. In n-dodecyl-β-d-maltoside (DDM) or n-undecyl-β-d-maltoside (UDM), WT MelBSt binds melibiose with an affinity similar to that in the membrane. However, with WT MelBEc or MelBSt mutan...

Integral membrane proteins (IMPs) performing a variety of cell functions comprise a significant fraction of the proteins encoded in an organism's genome. Maltose-neopentyl glycol-3 (MNG-3) was invented as a novel detergent to extract IMPs from the cell membranes; MNG-3 has an inherent flexibility originating from its central carbon and its arms com...

Uniform hollow hydrogel microcapsules, composed of a graphene oxide platelet-patched shell, are fabricated in one step in a capillary-based microfluidic device. We demonstrate that patching a small amount of graphene oxide at the interfaces remarkably prevents the leakage of small molecules through the shell.

A new steroidal-based amphiphile (GCT-2) was prepared with high efficiency. This agent provided enhanced protein stability to a denaturation-sensitive membrane protein.

Membrane protein manipulation is known to be an extremely challenging task, mainly because of incompatibility between the hydrophobic surface area of proteins and the hydrophilic character of an aqueous medium. To avoid protein degradation resulting from this incompatibility, detergents are essential tools in the study of membrane proteins. However...