Macromolecular Conformation Research Articles

Quantification of Distributions of Local Proton Concentrations in Heterogeneous Soft Matter and Non-Anfinsen Biomacromolecules.

A new method to quantitatively analyze heterogeneous distributions of local proton densities around paramagnetic centers in unstructured and weakly structured biomacromolecules and soft matter is introduced, and its feasibility is demonstrated on aqueous solutions of stochastically spin-labeled polysaccharides. This method is based on the pulse EPR experiment ih-RIDME (intermolecular hyperfine relaxation-induced dipolar modulation enhancement). Global analysis of a series of RIDME traces allows for a mathematically stable transformation of the time-domain data to the distribution of local proton concentrations. Two pulse sequences are proposed and tested, which combine the ih-RIDME block and the double-electron-electron resonance (DEER) experiment. Such experiments can be potentially used to correlate the local proton concentration with the macromolecular chain conformation. We anticipate an application of this approach in studies of intrinsically disordered proteins, biomolecular aggregates, and biomolecular condensates.

Accurate Determination of the Average Rate Constant of Pyrene Excimer Formation for Pyrene-Labeled Macromolecules from the Analysis of Individual Fluorescence Decays with Sums of Exponentials.

The average rate constant (⟨k⟩) for pyrene excimer formation (PEF) between an excited and a ground-state pyrenyl label covalently attached to a pyrene-labeled macromolecule (PyLM) has been found to be an ideal parameter to probe macromolecular conformations due to its proportionality to the local concentration ([Py]loc) of pyrenyl labels in PyLM. To date, ⟨k⟩ has only been determined with the model-free analysis (MFA) involving the global analysis of the pyrene monomer and excimer fluorescence decays of PyLM. Unfortunately, the MFA is computationally demanding which prevents its widespread use. To circumvent this complication, a methodology is introduced that involves the analysis of individual fluorescence decays with sums of exponentials (SoE), which are commonly used in the analysis packages of commercial time-resolved fluorometers. The individual fluorescence decays of the pyrene monomer acquired with 286 PyLM were analyzed with a SoE to yield ⟨kSoE-M⟩. The strong correlation between ⟨kSoE-M⟩ and ⟨kMF⟩ obtained from the global MFA indicated that ⟨kSoE-M⟩ was a good representation of ⟨k⟩. Furthermore, the AE-/AE+ ratio, equal to the ratio of the sum of the negative pre-exponential factors over the sum of the positive pre-exponential factors, was determined by fitting the individual pyrene excimer fluorescence decays of the 286 PyLM with a SoE. AE-/AE+ was found to take a value between -1.0 and -0.8, indicating that the pyrenyl labels were not aggregated. This result indicated that [Py]loc was well described by ⟨kSoE-M⟩, so that ⟨kSoE-M⟩ could be used to describe the conformation of macromolecules in the same manner as ⟨kMF⟩. Consequently, the methodology based on the analysis of individual fluorescence decays with sums of exponentials to determine ⟨kSoE-M⟩ and AE-/AE+ provides a robust alternative to the use of the MFA for the study of PyLM to many scientists interested in the characterization of macromolecular conformations.

The Influence of a Microstructural Conformation of Oriented Floating Films of Semiconducting Polymers on Organic Device Performance.

Extended π-conjugation with backbone-planarity-driven π-π stacking dominates charge transport in semiconducting polymers (SCPs). The roles of SCP film morphology and macromolecular conformation concerning the substrate in influencing charge transport and its impact on device performance have been a subject of extensive debate. Face-on SCPs promote out-of-plane charge transport primarily through π-π stacking, with conjugated polymeric chains assisting transport in connecting crystalline domains, whereas edge-on SCPs promote in-plane charge transport primarily through conjugation and π-π stacking. In this work, we fabricated three different types of devices, namely, organic field effect transistors, organic Schottky diodes, and organic bistable memristors, as representatives of planar and vertical devices. We demonstrate that a planar device, i.e., an organic field effect transistor, performs well in an edge-on conformation exhibiting a field-effect mobility of 0.12 cm2V-1s-1 and on/off ratio >104, whereas vertical devices, i.e., organic Schottky diodes and organic memristors, perform well in a face-on conformation, exhibiting exceptionally high on/off ratios of ~107 and 106, respectively.

Theory of Liquids for Studying the Conformational Flexibility of Biomolecules with Reference Interaction Site Model Approximation

The theory of fluids is used to modify the integral equations of the reference interaction site model (RISM) approximation. Its applicability to the study of biomolecules solvation is evaluated. Unlike traditional RISM applications, the new integral equation contains an intramolecular correlation matrix that only needs to be calculated once. This allows us to bypass the effort of repeatedly solving RISM equations and the time-consuming averaging of values obtained for each time point of a molecular trajectory. The new approach allows for the assessment of the conformational transience of dissolved molecules while taking into account the effects of solvation. The free energy of oxytocin, which is a peptide hormone, as well as self-assembled ionic peptide complexes calculated using both the traditional RISM and the new RISM with average matrix (RISM-AM) approach are estimated. The free energy of oxytocin calculated using RISM-AM shows that the statistical error does not exceed the error obtained by standard averaging of solutions in the RISM equation. Despite the somewhat ambiguous results obtained for ionic peptide self-assembly using RISM-AM with Lennard–Jones repulsion correction, this method can still be considered applicable for fast molecular dynamics analysis. Since the required computational power can be reduced by at least two orders of magnitude, the medium-matrix RISM is indeed a highly applicable tool for studying macromolecular conformations as well as corresponding solvation effects.

Advancing Antiamyloidogenic Activity by Fine-Tuning Macromolecular Topology.

Amyloid β peptide can aggregate into thin β-sheet fibrils or plaques deposited on the extracellular matrix, which is the hallmark of Alzheimer's disease. Multifunctional macromolecular structures play an important role in inhibiting the aggregate formation of amyloidogenic materials and thus are promising candidates with antiamyloidogenic characteristics for the development of next-generation therapeutics. In this study, we evaluate how small differences in the dendritic topology of these structures influence their antiamyloidogenic activity by the comparison of "perfectly dendritic" and "pseudodendritic" macromolecules, both decorated with mannose units. Their compactness, the position of surface units, and the size of glyco-architectures influence their antiamyloidogenic activity against Aβ 40, a major component of amyloid plaques. For the advanced analysis of the aggregation of the Aβ peptide, we introduce asymmetric flow field flow fractionation as a suitable method for the quantification of large and delicate structures. This alternative method focuses on the quantification of complex aggregates of Aβ 40 and glycodendrimer/glyco-pseudodendrimer over different time intervals of incubation, showing a good correlation to ThT assay and CD spectroscopy results. Kinetic studies of the second-generation glyco-pseudodendrimer revealed maximum inhibition of Aβ 40 aggregates, verified with atomic force microscopy. The second-generation glyco-pseudodendrimer shows the best antiamyloidogenic properties confirming that macromolecular conformation in combination with optimal functional group distribution is the key to its performance. These molecular properties were validated and confirmed by molecular dynamics simulation.

Macromolecular Conformation of Low-Generation PAMAM Dendrimers Probed by Pyrene Excimer Formation

A series of pyrene-labeled PAMAM dendrimers (PyCX-PAMAM-GY, where X (=4, 8, or 12) and Y (=0, 1, or 2) represent the number of atoms in the pyrenyl linker and the dendrimer generation, respectively) were studied by acquiring their time-resolved fluorescence decays in N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). The fluorescence decays were fitted globally according to the model-free analysis (MFA), which yielded the average rate constant ⟨k⟩ for pyrene excimer formation (PEF). ⟨k⟩ was compared with the local pyrene concentration [Py]loc inside the dendrimers, which was calculated by assuming that the segments constituting the dendrimer interior obey Gaussian statistics. ⟨k⟩ was found to increase linearly with [Py]loc in both solvents, but the straight lines had different slopes due to differences in solvent viscosity and polarity. These differences were accounted for by dividing ⟨k⟩ by kdiff, which is the bimolecular rate constant for PEF generated by n-hexyl-1-pyrenebutyramide used as a model compound. The ⟨k⟩/kdiff ratios obtained for all the PyCX-PAMAM-GY samples in DMF and DMSO collapsed onto a single master line where ⟨k⟩/kdiff increased linearly with [Py]loc. The strong correlation found between ⟨k⟩ and [Py]loc suggested that the oligomeric segments constituting the interior of the low-generation (Y = 0, 1, and 2) PAMAM dendrimers obeyed Gaussian statistics. This fact was further supported by using the Gaussian approximation to calculate the radius of gyration (Rg) of PAMAM dendrimers and compare them to the Rg values obtained by molecular dynamics simulations. The excellent agreement obtained between the two sets of Rg values validated the assumption. Furthermore, the direct relationship between ⟨k⟩ and [Py]loc established in this study demonstrates that ⟨k⟩ provides a quantitative measure of the internal density of the dendrimers, an observation with considerable implications for the quantitative conformational characterization of macromolecules with a complex architecture in solution.

Synchrotron-Based Fourier-Transform Infrared Micro-Spectroscopy of Cerebrospinal Fluid from Amyotrophic Lateral Sclerosis Patients Reveals a Unique Biomolecular Profile.

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, with the most common adult-onset neurodegenerative disorder affecting motoneurons. Although disruptions in macromolecular conformation and homeostasis have been described in association with ALS, the underlying pathological mechanisms are still not completely understood, and unambiguous biomarkers are lacking. Fourier Transform Infrared Spectroscopy (FTIR) of cerebrospinal fluid (CSF) is appealing to extensive interest due to its potential to resolve biomolecular conformation and content, as this approach offers a non-invasive, label-free identification of specific biologically relevant molecules in a few microliters of CSF sample. Here, we analyzed the CSF of 33 ALS patients compared to 32 matched controls using FTIR spectroscopy and multivariate analysis and demonstrated major differences in the molecular contents. A significant change in the conformation and concentration of RNA is demonstrated. Moreover, significantly increased glutamate and carbohydrates are found in ALS. Moreover, key markers of lipid metabolism are strongly altered; specifically, we find a decrease in unsaturated lipids and an increase in peroxidation of lipids in ALS, whereas the total amount of lipids compared to proteins is reduced. Our study demonstrates that FTIR characterization of CSF could represent a powerful tool for ALS diagnosis and reveals central features of ALS pathophysiology.

Aβ40 Aggregation under Changeable Conditions.

Homeostasis is crucial for cell function, and disturbances in homeostasis can lead to health disorders. Under normal conditions, intracellular pH is maintained between 7.35 and 7.45. Altered endosomal and lysosomal pH together with a general drop in brain pH are associated with the aggregation of amyloid-β-peptide (Aβ) and the development of Alzheimer's disease. Under acidic conditions, close to the Aβ isoelectric point, the absence of charges favors the formation of intermolecular contacts and promotes aggregation. Here, we analyzed how pH levels affect the aggregation of Aβ40 considering the variations in brain pH and the coexistence of different aggregated conformations. Our results suggest that different macromolecular conformations can interact with each other and influence the aggregation process. In addition, we showed that neutral pH and physiological salt concentrations favor a slow aggregation, resulting in ordered, stable fibrils, with low cytotoxic effects. Overall, we highlight the complexity of the aggregation processes occurring in different physiological and pathological environments.

Development of Polyurethane/Peptide-Based Carriers with Self-Healing Properties.

In situ-forming gels with self-assembling and self-healing properties are materials of high interest for various biomedical applications, especially for drug delivery systems and tissue regeneration. The main goal of this research was the development of an innovative gel carrier based on dynamic inter- and intramolecular interactions between amphiphilic polyurethane and peptide structures. The polyurethane architecture was adapted to achieve the desired amphiphilicity for self-assembly into an aqueous solution and to facilitate an array of connections with peptides through physical interactions, such as hydrophobic interactions, dipole-dipole, electrostatic, π-π stacking, or hydrogen bonds. The mechanism of the gelation process and the macromolecular conformation in water were evaluated with DLS, ATR-FTIR, and rheological measurements at room and body temperatures. The DLS measurements revealed a bimodal distribution of small (~30-40 nm) and large (~300-400 nm) hydrodynamic diameters of micelles/aggregates at 25 °C for all samples. The increase in the peptide content led to a monomodal distribution of the peaks at 37 °C (~25 nm for the sample with the highest content of peptide). The sol-gel transition occurs very quickly for all samples (within 20-30 s), but the equilibrium state of the gel structure is reached after 1 h in absence of peptide and required more time as the content of peptide increases. Moreover, this system presented self-healing properties, as was revealed by rheological measurements. In the presence of peptide, the structure recovery after each cycle of deformation is a time-dependent process, the recovery is complete after about 300 s. Thus, the addition of the peptide enhanced the polymer chain entanglement through intermolecular interactions, leading to the preparation of a well-defined gel carrier. Undoubtedly, this type of polyurethane/peptide-based carrier, displaying a sol-gel transition at a biologically relevant temperature and enhanced viscoelastic properties, is of great interest in the development of medical devices for minimally invasive procedures or precision medicine.

Efficient and accurate multi-scale simulation for viscosity mechanism of konjac glucomannan colloids

The viscosity is a foundational parameter of biomacromolecule in the food industry. The viscosity of macroscopic colloids is closely related to the dynamical behaviors of mesoscopic biomacromolecule clusters, which are difficult to be investigated at molecular resolution by common methods. In this study, based on experimental data, multi-scale simulations combining microscopic molecular dynamics simulation, mesoscopic Brownian dynamics simulation, and macroscopic flow field construction were used to investigate the dynamical behaviors of mesoscopic clusters of konjac glucomannan (KGM) colloids (~500 nm) over a long time (~100 ms). Numerical statistical parameters of the mesoscopic simulation of macroscopic clusters were proposed and proved to represent the viscosity of colloids. Based on the intermolecular interaction and macromolecular conformation, the mechanism of the shear thinning effect was revealed as both the regular arrangement of macromolecules at low shear rates (<100 s−1) and structural collapse of macromolecules at high shear rates (>500 s−1). Then, the effect of molecular concentration, molecular weight, and temperature on the colloid viscosity and cluster structure of KGM colloids was investigated by experiments and simulations. This study provides a novel multi-scale numerical method and insight into the viscosity mechanism of biomacromolecule.

Discrete Oligocarbamates Exhibit Sequence-Dependent Fluorescence Emission and Quenching.

The encoded precision of biological polymers enables a few simple monomers (e.g., four nucleotides in nucleic acids) to create complex macromolecular structures that accomplish a myriad of functions. Similar spatial precision in synthetic polymers and oligomers can be harnessed to create macromolecules and materials with rich and tunable properties. Recent exciting advances in iterative solid- and solution-phase synthetic strategies have led to the scalable production of discrete macromolecules, which in turn has enabled the study of sequence-dependent material properties. Our recent example of a scalable synthetic strategy using inexpensive vanillin-based monomers to create sequence-defined oligocarbamates (SeDOCs) enabled the preparation of isomeric oligomers with different thermal and mechanical properties. We show that unimolecular SeDOCs also exhibit sequence-dependent dynamic fluorescence quenching that persists from solution to the solid phase. We detail the evidence for this phenomenon and show that changes in fluorescence emissive properties are dependent on macromolecular conformation, which in turn is driven by sequence.

A new Raman spectroscopy‐based method for monitoring the crystallinity ratio of polyethylene terephthalate

AbstractTracking the Raman scattering bands of polyethylene terephthalate (PET) during thermal heating has allowed to establish criteria for monitoring the crystallinity ratio within a few seconds. The existing criteria, based on Raman bands at 998 cm−1 and at 1096 cm−1, present certain disparities from the crystallinity ratio given by the total heat flow in differential scanning calorimetry (DSC). Based on the evolution of the Raman bands, a newfound method allowing the effective calculation of crystallinity ratio is proposed. For the same, the band at 1727 cm−1, which is characteristic of the C=O carbonyl bonds of the ester group of PET, is used. The new criterion, designated r1727,2, was compared and validated by DSC and XRD. This novel approach also provides access to information on the various conformational states of the bonds under study, that is, their proportions and positions with respect to the plane of the macromolecule aromatic rings. Evidently, this allows to reveal the characteristic thermal behavior of the PET microstructure such as the glass transition, crystallization, and melting. This method can be useful for the close detection, quantification, understanding, and tracing of the micromechanisms involved at the macromolecular conformations scale during thermal cycles.

Probing RNA Conformations Using a Polymer-Electrolyte Solid-State Nanopore.

Nanopore systems have emerged as a leading platform for the analysis of biomolecular complexes with single-molecule resolution. The conformation of biomolecules, such as RNA, is highly dependent on the electrolyte composition, but solid-state nanopore systems often require high salt concentration to operate, precluding analysis of macromolecular conformations under physiologically relevant conditions. Here, we report the implementation of a polymer-electrolyte solid-state nanopore system based on alkali metal halide salts dissolved in 50% w/v poly(ethylene) glycol (PEG) to augment the performance of our system. We show that polymer-electrolyte bath governs the translocation dynamics of the analyte which correlates with the physical properties of the salt used in the bath. This allowed us to identify CsBr as the optimal salt to complement PEG to generate the largest signal enhancement. Harnessing the effects of the polymer-electrolyte, we probed the conformations of the Chikungunya virus (CHIKV) RNA genome fragments under physiologically relevant conditions. Our system was able to fingerprint CHIKV RNA fragments ranging from ∼300 to ∼2000 nt length and subsequently distinguish conformations between the co-transcriptionally folded and the natively refolded ∼2000 nt CHIKV RNA. We envision that the polymer-electrolyte solid-state nanopore system will further enable structural and conformational analyses of individual biomolecules under physiologically relevant conditions.

Unraveling the Implications of Macromolecular Orientation on the Planar and Vertical Charge Transport in Organic Electronic Devices

The role of film morphology of conjugated polymers (CPs) and their macromolecular conformation with respect to the substrate in governing charge transport and overall device performances has been a matter of debate. The nature of the macromolecular orientation of CPs in thin films has a pivotal role in controlling the performance of planar and sandwich devices. Thin-film characterizations unveiled that spin-coated films are isotropic with mixed edge-on/face-on conformation, whereas unidirectional floating film transfer method (UFTM) films are anisotropic with edge-on-oriented micrometer-sized ordered domains. To unravel the explicit role of molecular orientation on device performance, two types of devices, organic Schottky diodes (OSDs) for out-of-plane carrier transport and organic field-effect transistors (OFETs) for in-plane charge transport, were fabricated and characterized. Isotropic and relatively low crystalline spin-coated films exhibited superior transport characteristics in the out-of-plane direction than UFTM films irrespective of the crystallinity. On the other hand, edge-on-oriented UFTM thin films demonstrated remarkably enhanced in-plane charge transport with more than two orders of magnitude of enhancement in the field-effect mobility. The nature of molecular orientation of different films is significantly correlated with the performance of the OSDs and OFETs.

Mix-and-Inject Serial Femtosecond Crystallography to Capture RNA Riboswitch Intermediates.

Time-resolved structure determination of macromolecular conformations and ligand-bound intermediates is extremely challenging, particularly for RNA. With rapid technological advances in both microfluidic liquid injection and X-ray free electron lasers (XFEL), a new frontier has emerged in time-resolved crystallography whereby crystals can be mixed with ligand and then probed with X-rays (mix-and-inject) in real time and at room temperature. This chapter outlines the basic setup and procedures for mix-and-inject experiments for recording time-resolved crystallographic data of riboswitch RNA reaction states using serial femtosecond crystallography (SFX) and an XFEL.

Molecular Dynamics Modeling Based Investigation of the Effect of Freezing Rate on Lysozyme Stability.

The stability of protein drug products frozen during fill finish operations is greatly affected by the freezing rate applied. Non-optimal freezing rates may lead to the denaturation of protein's complex macromolecular conformation. However, limited work has been done to address the effect of different freezing rates on protein stability at nano-scale level. The stability of a model protein, lysozyme, was investigated at atomic and molecular scale under varying freezing rates and moving ice-water interface. Ice seeding approach was adopted to initiate ice formation in this present simulation. The faster freezing rate (11-12K/490ns) applied resulted in overall smaller ice fraction within the simulation box with a larger freeze-concentrated liquid (FCL) region. Consequently, the faster freezing rate better maintained protein stability with less secondary structure deviations, higher hydration level and structural compactness, and less fluctuations at individual residues than observed following slow (5-6K/490ns) and medium (7-8K/490ns) freezing rates. The present study also identified the residues near and within helices 3, 6, 7, and 8 dominate the structural instability of the lysozyme at 247K freezing temperature. For the first time, ice formation in therapeutic protein solution was studied "non-isothermally" at different freezing rates using molecular dynamics simulations. Thus, a good understanding of freezing rates on protein instability was revealed by applying the developed computational model.

Multiscale Structure of Poly(ionic liquid)s in Bulk and Solutions by Small-Angle Neutron Scattering

Poly(ionic liquid)s (PILs), similar to their ionic liquid (IL) analogues, present a nanostructure arising from local interactions. The influence of this nanostructure on the macromolecular conformation of polymer chains is investigated for the first time by means of an extensive use of small angle neutron scattering on a series of poly(1-vinyl-3-alkylimidazolium)s with varying alkyl side-chain length and counter-anion both in bulk and in dilute solutions. Radii of gyration are found to increase with the side-chain length in solution as a consequence of crowding interactions between neighboring monomers. In bulk, however, a non monotonic evolution of the radius of gyration reflects a change in chain flexibility and a potential screening of electrostatic interactions. Additionally at smaller scale, SANS provides an experimental estimation of both the chain diameter and the correlation length between neighboring chains, comparison of which unveils clear evidence of interdigitation of the alkyl side-chains. These structural features bring precious insights in the understanding of the dynamic properties of PILs.

Accurate Sampling of Macromolecular Conformations Using Adaptive Deep Learning and Coarse-Grained Representation.

Conformational sampling of protein structures is essential for understanding biochemical functions and for predicting thermodynamic properties such as free energies. Where previous approaches rely on sequential sampling procedures, recent developments in generative deep neural networks rendered possible the parallel, statistically independent sampling of molecular configurations. To be able to accurately generate samples of large molecular systems from a high-dimensional multimodal equilibrium distribution function, we developed a hierarchical approach based on expressive normalizing flows with rational quadratic neural splines and coarse-grained representation. Furthermore, system specific priors and adaptive and property-based controlled learning was designed to diminish the likelihood for the generation of high-energy structures during sampling. Finally, backmapping from a coarse-grained to fully atomistic representation is performed through an equivariant transformer model. We demonstrate the applicability of the method on the one-shot configurational sampling of a protein system with more than a hundred amino acids. The results show enhanced expressivity that diminish the invertibility constraints inherent in the normalizing flow framework. Moreover, the capacity of the hierarchical normalizing flow model was tested on a challenging case study of the folding/unfolding dynamics of the peptide chignolin.

Universally Accessible Structural Data on Macromolecular Conformation, Assembly, and Dynamics by Small Angle X-Ray Scattering for DNA Repair Insights.

Structures provide a critical breakthrough step for biological analyses, and small angle X-ray scattering (SAXS) is a powerful structural technique to study dynamic DNA repair proteins. As toxic and mutagenic repair intermediates need to be prevented from inadvertently harming the cell, DNA repair proteins often chaperone these intermediates through dynamic conformations, coordinated assemblies, and allosteric regulation. By measuring structural conformations in solution for both proteins, DNA, RNA, and their complexes, SAXS provides insight into initial DNA damage recognition, mechanisms for validation of their substrate, and pathway regulation. Here, we describe exemplary SAXS analyses of a DNA damage response protein spanning from what can be derived directly from the data to obtaining super resolution through the use of SAXS selection of atomic models. We outline strategies and tactics for practical SAXS data collection and analysis. Making these structural experiments in reach of any basic and clinical researchers who have protein, SAXS data can readily be collected at government-funded synchrotrons, typically at no cost for academic researchers. In addition to discussing how SAXS complements and enhances cryo-electron microscopy, X-ray crystallography, NMR, and computational modeling, we furthermore discuss taking advantage of recent advances in protein structure prediction in combination with SAXS analysis.

Freeze-thaw and solvent-exchange strategy to generate physically cross-linked organogels and hydrogels of curdlan with tunable mechanical properties

Physical gels from natural polysaccharides present the advantage of no toxic cross-linking agents and no chemical modification during preparation. Herein, novel physical gels, transparent organogels and opaque hydrogels from the microorganism-derived (1,3)-β-D-glucan of curdlan were prepared in dimethyl sulfoxide (DMSO) using the freeze-thaw technique, followed by a solvent-exchange strategy with water. The mechanical and structural properties of these gels were investigated by rheology, scanning electron microscopy, attenuated total reflection infrared spectroscopy, wide-angle X-ray diffraction and small-angle X-ray scattering. Gelation mechanisms and intermolecular interaction models have also been proposed. The good solvent DMSO serves as both a crosslinker and a pore-foaming agent in organogels. The reversible macromolecular conformation changes and phase separation of curdlan endow the gels with reversible transparency, volume change and tunable mechanical strength. The new design strategy of facile preparation and performance tuning provides a platform for developing new organogels and sterile hydrogels of curdlan.