Understanding the interaction between graphene oxide (GO) and biomolecules is fundamentally essential, especially for disease- drug-related peptides proteins. In this study, GO was found to strongly interact with amino acids (tryptophan tyrosine), (Alzheimer's disease related amyloid beta 1-40 type 2 diabetes human islet polypeptide), proteins (drug-related bovine serum albumin) by fluorescence quenching, indicating a universal quencher tryptophan or tyrosine The quenching mechanism (Trp)...

Strain-promoted click chemistry of nucleosides and nucleotides with an azido group directly attached to the purine pyrimidine rings various cyclooctynes in aqueous solution at ambient temperature resulted efficient formation (3 min 3 h) fluorescent, light-up, triazole products. The 2- 8-azidoadenine reacted fused cyclopropyl cyclooctyne, dibenzylcyclooctyne, or monofluorocyclooctyne produce products functionalized hydroxyl, amino, N-hydroxysuccinimide, biotin moieties. 5-azidouridine...

Flavin adenine dinucleotide (FAD) is involved in important metabolic reactions where the biological function intrinsically related to changes conformation. In present work, FAD conformational were studied solution and gas phase by measuring fluorescence decay time ion-neutral collision cross sections (CCS, a trapped ion mobility spectrometer, TIMS) as of solvent conditions (i.e., organic content) gas-phase collisional partner N2 doped with molecules). Changes suggest that can exist four...

In the present work, kinetic intermediates of holo- and apo-myoglobin were studied by correlating ion-neutral collision cross section time resolved H/D back exchange rate simultaneously in a trapped ion mobility spectrometer coupled to mass (HDX-TIMS-MS). The high resolution TIMS cell permitted observation multiple IMS bands complementary molecular dynamics simulations resulted assignment candidate structures for each experimental condition (e.g., holo [M + 8H](+8)-[M 9H](+9) apo 9H](+9)-[M...

Study of the conformational dynamics and folding pathways i-motif DNA in solution gas-phase.

We have examined the photophysical properties of Zn(II) tetramethylpyridyl porphyrin (ZnT4MPyP) specifically encapsulated within cubioctahedral cavities a ZnHKUST metal- organic framework. The ZnT4MPyP exhibits Soret maxima at ∼458 nm that is bathochromically shifted relative to ZnT4PyP in ethanol solution (Soret centered 440 nm). corresponding emission spectra exhibit resolvable bands 636 and 677 single broad band with shoulder situated near ∼660 nm. fluorescence lifetime also perturbed...

Globular proteins, such as cytochrome c (cyt c), display an organized native conformation, maintained by a hydrogen bond interaction network. In the present work, structural interrogation of kinetically trapped intermediates cyt was performed correlating ion-neutral collision cross section (CCS) and charge state with starting solution conditions time after desolvation using induced activation (CIA), time-resolved hydrogen/deuterium back exchange (HDX) ion mobility spectrometry-mass...

Quartz nanopipettes with attoliter sensing volumes can be potentially used as a label-free method to quantitatively characterize protein–protein interactions, based on charge mechanism.

Numerical calculations of the free energy first electron transfer in genetically modified reaction centers from Rhodobacter (Rb.) sphaeroides and Rb. capsulatus were carried out pH 5 to 11. The multiconformation continuum electrostatics (MCCE) method allows side chain, ligand, water reorientation be embedded Boltzmann distribution cofactor amino acid ionization states. mutation sites whose effects have been modeled are L212 L213 (the L polypeptide) two M polypeptide, M43(44) M231(233) (Rb....

Fluorescent N-phenyl-4-aminoquinazoline probes targeting the ATP-binding pocket of ERBB family receptor tyrosine kinases are reported. Extension aromatic quinazoline core with fluorophore "arms" through substitution at 6- position phenyl, styryl, and phenylbutadienyl moieties was predicted by means TD-DFT calculations to produce tunable photoexcitation energies excited states possessing charge-transfer character. Optical spectroscopy identified several synthesized that nonemissive in aqueous...

In the reaction centers from purple photosynthetic bacterium Rhodobacter capsulatus, we have determined that residue L212Glu, situated near secondary quinone acceptor QB, modulates free energy level of reduced primary molecule QA- at high pH. Even though distance between L212Glu and QA is 17 Å, our results indicate an apparent interaction them 30 ± 18 meV. This was measured by quantitating stoichiometry partial proton uptake upon formation as a function pH in four mutant strains which lack...

Distinct local dynamics of Aβ_1–23 amyloid formation are characterized using an unnatural amino acid <italic>p</italic>-cyanophenylalanine as a spectroscopic probe.

The Cu(I)- or Ag(I)-catalyzed cycloaddition between 8-ethynyladenine guanine nucleosides and TMSN3 gave 8-(1-H-1,2,3-triazol-4-yl) in good yields. On the other hand, reactions of 5-ethynyluracil cytosine with led to chemoselective formation triazoles via Cu(I)-catalyzed vinyl azides hydroazidation. These a minimalistic triazolyl modification showed excellent fluorescent properties 8-(1-H-1,2,3-triazol-4-yl)-2′-deoxyadenosine (8-TrzdA), exhibiting quantum yield 44%. 8-TrzdA 5′-triphosphate...

Perfluorooctanoic acid (PFOA), a persistent organic pollutant known to cause adverse health effects, strongly binds human serum albumin (HSA). β-Cyclodextrin (β-CD), nontoxic cyclic sugar, complexes PFOA in host-guest complex and has been proposed for environmental remediation of PFOA. The interactions between HSA, PFOA, β-CD were investigated order determine if can reverse the binding with potential therapeutic applications toward exposure 19F Nuclear magnetic resonance (NMR), circular...

DREAM (also known as K(+) channel interacting protein 3 and calsenilin) is a calcium binding an active modulator of KV4 channels in neuronal cells well novel Ca(2+)-regulated transcriptional modulator. has also been associated with the regulation Alzheimer's disease through prevention presenilin-2 fragmentation. Many interactions its partners (Kv4, calmodulin, DNA, drugs) have shown to be dependent on calcium. Therefore, understanding structural changes induced by metals essential for...

Interactions between sodium dodecyl sulfate (SDS) and horse heart myoglobin (Mb) at surfactant concentrations below the critical micelle concentration have been studied using steady-state transient absorption spectroscopies photoacoustic calorimetry. SDS binding to Mb induces a heme transition from high-spin five-coordinate low-spin six-coordinate in met- deoxyMb, with distal His residue likely be sixth ligand. The is complete an of ∼350 μM ∼700 for respectively. ΔGH2O m values determined...

Neuroglobin belongs to the family of hexacoordinate hemoglobins and has been implicated in protection neuronal tissue under hypoxic ischemic conditions. Here we present transient absorption photoacoustic calorimetry studies CO photodissociation bimolecular rebinding neuroglobin focusing on ligand migration process role distal pocket residues (His64 Val68) two Cys (Cys55 Cys120). Our results indicate that His64 a minor impact between heme protein exterior, whereas Val68 side chain regulates...

Abstract DNA topology plays essential roles in several fundamental biological processes, such as replication, recombination, and transcription. Typically agarose gel electrophoresis is employed to study topology. Since time-consuming labor intensive, it desirable develop other methods, fluorescence-based for studies. In this paper we report the synthesis of a type unique fluorescence-labeled molecules that can be used topoisomerases by fluorescence resonance energy transfer (FRET)....