The yeast prion protein Sup35 is a translation termination factor, whose activity modulated by sequestration into self-perpetuating amyloid. prion-determining domain, NM, consists of two distinct regions: an amyloidogenic N terminus domain (N) and charged solubilizing middle region (M). To gain insight conversion, we used single-molecule fluorescence resonance energy transfer (SM-FRET) correlation spectroscopy to investigate the structure dynamics monomeric NM. Low concentrations in these...

Biomolecular condensates formed via phase separation of proteins and nucleic acids are thought to perform a wide range critical cellular functions by maintaining spatiotemporal regulation organizing intracellular biochemistry. However, aberrant transitions implicated in multitude human diseases. Here, we demonstrate that two neuronal proteins, namely tau prion, undergo complex coacervation driven domain-specific electrostatic interactions yield highly dynamic, mesoscopic liquid-like...

We have investigated the fibrillation propensity of different conformational isomers an archetypal, all α-helical protein, namely, bovine serum albumin (BSA), under pH conditions and ionic strengths using fluorescence circular dichroism (CD) spectroscopy. At low higher protein concentration, partially folded conformers associate to form oligomers that are converted into ordered amyloid-like fibrils when incubated at elevated temperature. elucidated mechanism fibril formation, especially...

Liquid-liquid phase separation occurs via a multitude of transient, noncovalent, and intermolecular interactions resulting in transition intrinsically disordered proteins/regions (IDPs/IDRs) other biopolymers into mesoscopic, dynamic, nonstoichiometric, supramolecular condensates. Here we present unique case to demonstrate that unusual conformational expansion events coupled with solvation fluctuations drive tau, an IDP associated Alzheimer's disease. Using intramolecular excimer emission as...

Some amyloid-forming polypeptides are associated with devastating human diseases and others provide important biological functions. For both, oligomeric intermediates appear during amyloid assembly. Currently we have few tools for characterizing these conformationally labile discerning what governs their benign versus toxic states. Here, examine in the assembly of a normal, functional amyloid, prion-determining region yeast Sup35 (NM). During assembly, NM formed variety oligomers different...

Significance Biology has evolved to achieve precise spatiotemporal control of crucial cellular functions through liquid–liquid phase separation highly flexible proteins and nucleic acids into membraneless organelles. However, these liquid-like intracellular condensates can undergo irreversible transitions solid-like aggregates associated with deadly human diseases. Here, we show that a pathological truncation variant the prion protein comprising N-terminal unstructured domain spontaneously...

Biomolecular condensation via liquid-liquid phase separation of proteins and nucleic acids is associated with a range critical cellular functions neurodegenerative diseases. Here, we demonstrate that complex coacervation the prion protein α-synuclein within narrow stoichiometry results in formation highly dynamic, reversible, thermo-responsive liquid droplets domain-specific electrostatic interactions between positively-charged intrinsically disordered N-terminal segment acidic C-terminal...

The bacterial chromosome, known as its nucleoid, is an amorphous assemblage of globular nucleoprotein domains. It exists in a state phase separation from the cell's cytoplasm, irregularly-shaped, membrane-less, intracellular compartment. This (the nature which remains largely unknown) maintained through generations ad infinitum. Here, we show that HU and Dps, two most abundant nucleoid-associated proteins (NAPs) Escherichia coli, undergo spontaneous complex coacervation with different forms...

Biomolecular condensates formed via phase separation of proteins and nucleic acids are thought to be associated with a wide range cellular functions dysfunctions. We dissect critical molecular events an intrinsically disordered prion-like low-complexity domain Fused in Sarcoma by performing single-molecule studies permitting us access the wealth information that is skewed conventional ensemble experiments. Our FRET experiments reveal coexistence two conformationally distinct subpopulations...

Biomolecular condensates formed via phase separation of intrinsically disordered proteins/regions (IDPs/IDRs) and nucleic acids are associated with cell physiology disease. Water makes up for ∼60-70% the condensate volume is thought to influence complex interplay chain-chain chain-solvent interactions, modulating mesoscale properties condensates. The behavior water in key roles protein hydration driving remain elusive. Here, we employ single-droplet vibrational Raman spectroscopy illuminate...

Abstract Hendra virus (HeV) is a biosafety level 4 human pathogen belonging to the Henipavirus genus within Paramyxoviridae family. In HeV, phosphoprotein‐encoding gene also drives synthesis of V and W proteins that are two major players in host innate immune response evasion. These three share common intrinsically disordered N‐terminal domain (NTD) have distinct C‐terminal domains. We recently reported ability short region (i.e., PNT3), located shared NTD, form fibrils. subsequently...

Efficient gelation of aqueous fluids by a novel tripodal trischolamide generates chiral hydrophobic pockets in the gel network. A yellow to green color change (see absorbance spectra) presence bromophenol blue (BPBH) indicates formation gel. The bound (anionic) dye (BPB−) shows induced circular dichroism, which is indicative environment.

Liquid-liquid phase separation of intrinsically disordered proteins into mesoscopic, dynamic, liquid-like supramolecular condensates is thought to govern critical cellular functions. These can mature from a functional state pathological gel-like or solid-like state. Here, we present unique case demonstrate that an unusual cascade intermolecular charge-transfer coupled with multitude transient noncovalent interactions and conformational fluctuations promote liquid condensation pH-responsive,...

Abstract Biomolecular condensates formed via liquid-liquid phase separation (LLPS) are involved in a myriad of critical cellular functions and debilitating neurodegenerative diseases. Elucidating the role intrinsic disorder conformational heterogeneity intrinsically disordered proteins/regions (IDPs/IDRs) these phase-separated membrane-less organelles is crucial to understanding mechanism formation regulation biomolecular condensates. Here we introduce unique single-droplet surface-enhanced...

A tripodal cholamide-based hydrogel has been employed as a template to synthesize inorganic nanotubes. Besides nanotubes of oxides such SiO2, TiO2, ZrO2, WO3 and ZnO, sulfates the water-soluble ZnSO4 well BaSO4 have obtained using this method. An advantage use is that metal alkoxides are not required for synthesis oxide The characterized by X-ray diffraction transmission electron microscopy.

Tripodal cholamide 1 is a supergelator of aqueous fluids. A variety physical techniques, including cryo-transmission electron microscopy (TEM), circular dichroism (CD), steady-state fluorescence, time-resolved and dynamic light-scattering, were employed to understand the structure dynamics gel. Fluorescent probes [ANS (8-anilinonaphthalene-1-sulfonic acid) pyrene] reported two critical aggregation concentrations (CAC1 CAC2) in predominantly media, with minimum gel concentration (MGC) being...

Membrane-induced disorder-to-helix transition of α-synuclein, a presynaptic protein, has been implicated in number important neuronal functions as well the etiology Parkinson's disease. In order to obtain structural insights membrane-bound α-synuclein at residue-specific resolution, we took advantage fact that protein is devoid tryptophan and incorporated single various residue positions along sequence. These tryptophans were used site-specific markers characterize dynamical aspects on...

Intrinsically disordered proteins (IDPs) or natively unfolded do not undergo autonomous folding into a well-defined 3-D structure and challenge the conventional structure–function paradigm. They are involved in multitude of critical physiological functions by adopting various structural states via order-to-disorder transitions maintaining their characteristics functional complexes. In recent times, there has been burgeoning interest investigation intriguing behavior IDPs using highly...