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A study was conducted to examine the complete covalent structures of two purified closely related antifungal compounds, which were observed by the experiments of TOCSY, NOESY, ROESY, [super 13]C HSQC 2D NMR, and ESI-MS and GC. Findings suggest that the antifungal compound interrupts normal membrane morphology.

Bovine submaxillary mucin and porcine gastric mucin have accelerated the rate of fatty acid p-nitrophenol ester hydrolysis up to 337 times and a carbon-carbon bond-forming Diels-Alder reaction between N-propylmaleimide and anthracene up to 200 times relative to the rates of the reference processes. The new properties of mucins to accelerate organic reactions have provided a new example of natural nonenzymatic proteins capable of promoting reactions of hydrophobic materials in aqueous solution.

The article studies caspase recruitment domain (CARD) of recombinant human apoptotic protease activating factor-1 (Apaf-1) can be induced to undergo amyloid-like fibrillation. Findings suggest a molten globule (MG) transition of the CARD at pH [less than]4.

The extrinsic multiple-emission probe 4'-(diethylamino)-3-hydroxyflavone (FE) was used to demonstrate the unique and distinct spectroscopic signatures for the amyloid fibrils formed by the wild type (WT) and mutant [alpha]-synuclein (AS) with subtle differences in their supramolecular structure. The observed sensitivity of a simple external probe to conformational alterations induced by point mutations provides new insight into key phenomena related to amyloid fibrils such as plasticity, polymorphism, propagation of structural features, and structure-function relationships underlying toxicity.

The structure of cross-[beta] nanotubes, which limit the number of potential binding sites, is exploited to interrogate cross-[beta] laminate grooves. The broad red-shifted ultraviolet (UV) signature of Congo Red (CR) bound to amyloid is explained by semiempirical quantum calculations that have supported the existence of a precise network of J- and H-CR aggregates.

X-ray reflectivity (XRR) measurements are carried out on the islet amyloid polypeptide (IAPP) at lipid interfaces, providing a molecular level characterization of the first steps of the lipid-induced fibrillation process of IAPP. The studies have shown that the polyphenolic red wine compound resveratrol has inhibited IAPP aggregation in the presence of aggregation-fostering negatively charged lipid interfaces, disclosing its potential as a drug candidate for type-II diabetes mellitus (T2DM).

The high-resolution structure of rat islet amyloid polypeptide (IAPP or amylin) in the membrane-mimicking detergent micelles composed of dodecylphosphocholine was solved to understand the nature of transient [alpha]-helical intermediate state of amyloid fibrils and the difference in toxicity between the rat and human versions of IAPP. The comparison to the detergent-bound structures of other IAPP variants indicated that the N-terminal region might play a crucial role in the self-association and toxicity of IAPP by controlling access to the putative dimerization interface on the hydrophobic face of the amphipathic helix.

Quantum dots multifunctionalized with the amyloid protein [alpha]-synuclein which act at nanomolar concentrations as very potent inducers of the aggregation of micromolar-millimolar bulk concentrations of the protein in vitro and in cells are reported. The combination with a tetracysteine-tagged form of [alpha]-synuclein specific for fluorogenic biarsenicals which constitutes a very sensitive system could be applied to study pathological amyloid formation in cells.

The molecular mechanisms of membrane permeabilization induced by N-preTM and PreTM-C, two peptides derived from membrane-proximal external region (MPER) of the human immunodeficiency virus type-1 envelope glycoprotein 41 subunit are analyzed to understand their tendency to associate with the bilayer interface or to transfer into the hydrocarbon core, respectively. The result obtained supported the functional segmentation of gp41 membrane regions into hydrophobic subdomains which might expose neutralizing epitopes and induce membrane-disrupting effects following distinct patterns during the fusion cascade.

Atomic force microscopy images and dynamic light scattering measurements are used to understand the mechanism underlying the solubilization of insulin fibrils by the aqueous solutions of dimethyl sulfoxide (DMSO) without perturbing their [beta]-pleated structure. The findings revealed that the DMSO-induced ensembles of insulin molecules are closely related to elementary building blocks of amyloid fibrils.

A combination of biochemical and ultrastructural techniques were employed to gain insight into the ability of myelin basic protein (MBP) to inhibit the [beta]-sheet fibrillar assembly of the normal A[beta]42 peptide. The results obtained provide insight into the role of MBP towards regulation of the deposition of A[beta]42 and the early formation of amyloid plaques in Alzheimer's disease.

Tethering technology to discover small molecule fragment ligands that bind to the enzyme active site was utilized to survey BACE-1 ([beta]-site amyloid precursor protein cleaving enzyme), a prominent target in Alzheimer's disease drug. The study identified aminobenzylpiperidine (ABP) ligands as a new type of nonpeptidic BACE-1 inhibitor motif that might serve as a starting point for the development of BACE-1-directed Alzheimer's disease therapeutics.

Gram-positive bacteria are probed with conformationally specific antibodies and have disclosed the existence of extracellular functional bacterial amyloid (FuBA) in mycolata species, as well as six other specific antibodies belonging to the phyla Actinobacteria and Firmicutes. The studies have shown that amyloid is widespread among gram-positive bacteria and might constitute an integral part of the spore and the cellular envelope.

Pulsed field gradient NMR spectroscopy is used for showing that the monomeric form of the toxic, amyloidogenic human variant of islet amyloid polypeptide (hIAPP) has adopted a temperature dependent compact folded conformation that is absent in both the nontoxic and nonamyloidogenic rat variant of IAPP and absent in hIAPP at low temperatures. The absence of small oligomeric species in solution has showed the formation of small ion channels by hIAPP, which has proceeded by aggregation of monomeric IAPP on the membrane, rather that by the insertion of preformed structures oligomers from the solution state.

The matrix-assisted laser desorption/ionization quadrupole time-of-flight (MALDI Q-TOF) and liquid chromatography tandem mass spectrometry (LC-MS/MS) were used to identify the tyrosine phosphorylation sites in CD133 (prominin-1) as transmembrane glycoprotein expressed at the surface of normal and cancer stem cells. Identification of CD133 as a substrate for Src-family tyrosine kinases indicated that the cytoplasmic domain of CD133 might play significant role in the regulation of its functions.

A highly convergent synthesis of the sialic acid-rich biantennary N-linked glycan found in human glycoprotein hormones and its utility in preparing a fragment derived from the [beta]-domain of human Follicle-Stimulating Hormone (hFSH) are described. The synthetic glycan is used for preparing the glycosylated 20-27aa domain of the [beta]-subunit of hFSH under a Lansbury aspartylation protocol and it has provided protected [beta]-hFSH subunit functionalized with chitobiose at positions 7 and 24.

Several NMR studies are conducted to determine the structures of the different third variable region (V3) peptides of the HIV-1 envelope glycoprotein used for neutralizing antibodies. The cyclic V3 peptides are shown to exhibit a minimized conformational space, as compared to their linear counterparts.

Several studies are conducted to explain the expression, conformational stability and the interaction of the full-length ectodomain of the human immunodeficiency virus (HIV) gp41 glycoprotein. The gp41 folding in the low energy six helix bundle (SHB) conformation is shown to be extremely significant in reducing the membrane disruption effects in the domain.

Several biophysical methods are employed to explain the structural and binding properties of the different ligand complexes of PEB3, a glycoprotein adhesion obtained from Campylobacter jejuni. PEB3 is shown to act as a transport protein and can be easily used for utilizing the phosphates from the host.

A combination of solid-state nuclear magnetic resonance (SSNMR) and X-ray fiber diffraction studies is employed to explain the molecular architectures of the fibrils that are formed by the amyloidogenic segment of a medin. The various constraints that are imposed on the distances between the atomic sites in these fibrils are also discussed.

A structure-activity relationship study is conducted to identify the motif of the glycoprotein-folding sensor enzyme UDP-Glc: glycoprotein glucosyltransferase (UGCT). Various fluorescently labeled substrates for a highly sensitive detection of UCGT activity are also discussed.

The analytical ultracentrifugation approach is employed to explain the assembly of the convulxin (CVX) protein in a solution and surface plasmon resonance. CVX is shown to exhibit a dimeric nature in the solution, hence exhibiting the capability o binding eight copies of the platelet collagen receptor, glycoprotein VI.

The effect of the amyloidogenic and toxic peptide Islet Amyloid Polypeptide (IAPP or amylin) h[IAPP.sub.1-37] peptide and the nontoxic and nonamyloidogenic r[IAPP.sub.1-37] peptide on membranes is studied by a combination of DSC and solid-state NMR spectroscopy. The results have shown that IAPP might induce the formation of pores by the induction of excess membrane curvature and is used for designing compounds that can prevent the cell-toxicity of IAPP.

The results from NMR analysis of islet amyloid polypeptide (IAPP), a 37-amino acid polypeptide hormone of the calcitonin family which is colocalized and cosecreted with insulin in secretory granules of pancreatic islet [beta] cells are presented. The data obtained from NMR chemical shifts, [super 5]N relaxation, and 49 ns replica exchange molecular dynamic simulations indicated that the transiently populated helical structure in residues 11?18 are essential for interactions with insulin.

The wild-type (WT) and mutant amyloid precursor protein (APP) dimer conformations are predicted by replica-exchange molecular dynamics simulations by using the implicit membrane model IMM1. The simulations have shown large conformational differences between WT and mutant APP fragments in the membrane.

The properties and synthetic potential of two novel endoglycosidase-based glycosynthases, EndoM-N175A and EndoA-N171A, are described. The novel glycosynthases have provided a timely and potentially powerful tool for preparing various homogeneous N-glycoproteins carrying defined natural N-glycans.

A fast and convenient multistep purification procedure for the endogenous enzyme [gamma]-secretase, the protease complex that cleaves the Alzheimer's disease-associated [beta]-amyloid precursor protein (APP) and a number of other type I membrane proteins is reported. The developed procedure could also be used to purify [gamma]-secretase from cell lines stably overexpressing presenilin (PS) and biochemical analysis of [gamma]-secretase carrying a mutant catalytic subunit.

The intrinsic, global minimum secondary structure of the glycosylation-compatible consensus peptide sequon NGS has resembled QGS, but it is much less tightly bound. The structural changes involving interactions with the carboxamide side chain has provided evidence for the operation of structural constraints and a potential insight into the unique reactivity of the asparagine side chain toward enzymatic glycosylation.

A novel method of the NMR structural determination is developed by using segmental labeling of the glycan and the protein component by in vitro glycosylation. Highly homogeneously glycosylated proteins have allowed the determination of the structure of an N-linked glycoprotein from Campylobacter jejuni.

The first thermodynamic analysis of the interaction of gp120 with the N-terminal peptide of the CCR5 coreceptor is described. The results have highlighted the compounds containing sulfated aromatic groups as potential inhibitors of viral entry.

The synthesis of a library of modified chitobiose derivatives as potential peptide N-glycanase (PNGase) inhibitors responsible for the deglycosylation of N-linked glycoproteins that have an active site related to that of cysteine proteases is reported. The fluorescent probes are used for studying the selectivity of the inhibitors in cell lysates as well as whole cells.

Proteostasis is affected both by an adjustable proteostasis network capacity and protein folding energetics, which has determined the balance between folding efficiency, misfolding, protein degradation and aggregation. These therapeutic strategies, including combination therapies, have represented a new approach for treating a range of diverse human maladies.

The cloning, expression and characterization of a human candidate constitutive ENOX protein is described. Concentrated solutions of the purified candidate ENOX1 protein has irreversibly formed insoluble aggregates, which is devoid of enzymatic activity, resembling amyloid.

Several aspects of P-glycoprotein (Pgp)-cholesterol interactions are characterized to determine the effects of cholesterol result from inhibition of Pgp ATPase activity by the cholesterol-extracting reagent, methyl-[beta]-cyclodextrin. The results provide insight into the activity of cholesterol that likely modulates Pgp function via effects on drug-membrane partitioning and changes in the local lipid environment of the protein.

The incorporation of nucleic acid structural building blocks into amyloid to control morphology is demonstrated and novel template scaffolds are created for information storage. The nanotube surface asymmetry is not accessible and these archetypal assemblies have highlighted the ability to encode unique molecular information into amyloid assemblies for the construction of new robust nanoscale scaffolds.

The potential amyloidogenic property of each secondary structural element in a mouse prion protein (mPrP) is examined to gain insight into the structural mechanism of the conformational conversion process of prion and their relative significance for the formation of amyloid fibrils. The results revealed that the [alpha]-helix 2 region in mPrP is crucial for the nucleation-dependent replication process of the prion protein.

The effects of the rat and human versions of islet amyloid polypeptide (IAPP) on islet cells and model membranes are examined. The results have shown that the modulation of the peptide orientation in the membrane by His18 has played a main role in the toxicity of nonamyloidogenic forms of hIAPP.

The structures of the human and rat islet amyloid polypeptide ([IAPP.sub.1-19]) peptides in dodecylphosphocholine (DPC) micelles are examined. The difference in peptide topology in the membrane has corresponded to similar topology differences for the full-length human rat IAPP peptides, with the toxic human IAPP peptide adopting a transmembrane orientation and the nontoxic rat IAPP peptide bound to the surface of the membrane.

The propensity of different polypeptides is examined for amyloid fibril growth that is calculated by the association constant by using all-atom molecular dynamics (MD) with explicit solvent. The fibril growth properties of four tetrapeptides are examined.

A recombinantly produced polypeptide based on the sequence and domain structure of human tropoelastin is used to describe a method to deconstruct the self-assembly of elastin-like polypeptides into stages that is described and measured by individual parameters. The technique helps to demonstrate the distinct effects of fibulins, fibrillins, and matrix-associated glycoprotein (MAGP) on the kinetics of elastin self-assembly and on the morphology of the maturing elastin coacervate.

Solid-state nuclear magnetic resonance (SSNMR) is used for characterizing the amyloid-like fibrils formed by the peptide AcNH-SNNFGAILSS-CON[H.sub.2] (hIAP[P.sub.20-29) constituting residues 20-29 of amylin. The energies of formation for fibril form containing antiparallel and parallel [beta]-strands are similar when both configurations are stabilized by a core of hydrophobic contacts, which has implications for the relationship between amino acid sequence and amyloid polymorphism.

An efficient chemoenzymatic method for the construction of homogeneous N-glycoproteins is described. The findings provide new pathway for quick access of various homogeneous N-glycoproteins for structure-activity relationship studies and for biomedical applications.

The enhanced affinity of lectins to multivalent carbohydrates and glycoprotein's, which result in an initial fraction of lectin molecules that bind with very high affinity and dynamic motion, is demonstrated. The findings have significant implications for the mechanisms of binding of lectins to mucins and for other ligand-biopolymer interactions and clustered ligand-receptor systems.

Molecular dynamic simulations of an amidated 12-amino acid peptide denoted as LSFD in explicit water and at a water/vapor interface have revealed the conformational distribution of the peptide at a microscopic level. The main conformation of the peptide core has facilitated the design of inhibitors of LSFD aggregation as a test ground for computational therapeutic strategies against amyloid diseases.

The binding and interaction kinetics of model membranes of a peptide corresponding to segment 873-888 of the severe acute respiratory syndrome coronavirus (SARS-CoV) envelope spike (S) glycoprotein, peptide SARS.sub.IFP] as well as structural changes are reported. The data obtained shed light on the significant role of [SARS.sub.IFP] in the fusion of the viral and target cell membranes assisted by other membrane-active regions of the SARS-CoV S2 glycoprotein.