Azemiopsin, a novel polypeptide, was isolated from the Azemiops feae viper venom by combination of gel filtration and reverse-phase HPLC. Its amino-acid sequence (DNWWPKPPHQGPRPPRPRPKP) was determined by means of Edman degradation and mass spectrometry. It consists of 21 residues and, unlike similar venom isolates, does not contain cysteine residues. According ...

A 2nd generation polyamideamine (PAMAM) dendrimer bearing right-handed helices to its eight terminals was shown to accommodate eight left-handed helices via stereocomplex formation to generate molecular assemblies of disk structure with 13-14 nm diameter and 6 nm thickness.

HSP90 chaperones a large number of proteins and it plays essential roles in multiple signaling pathways to maintain protein homeostasis in the cytosol. In addition, HSP90 has been implicated in mediating recognition of lipopolysaccharide (LPS). However, no pharmacologic agents have been developed to interrogate this pathway. Herein we demonstrate that ...

The melting properties of various triblock copolymers with random coil middle blocks (100-800 amino acids) and triple helix-forming (Pro-Gly-Pro)n end blocks (n = 6-16) were compared. These gelatin-like molecules were produced as secreted proteins by recombinant yeast. The investigated series shows that the melting temperature (Tm) can be genetically engineered ...

Attachment of a vinyl group at guanine position 8 provides fluorescent properties of the nucleobase. Therefore, 8-vinylguanine was introduced as a 2-aminoethylglycine peptide nucleic acid (PNA) building block. Incorporation of the guanine analog in short PNA sequences by Fmoc solid phase peptide synthesis allowed the differentiation between hybridization states of ...

The synthesis of a sulfonamide-based transition-state (TS) analogue of enzymatic phosphohistidine dephosphorylation as an amino acid building block is presented, together with the proof-of-concept of its incorporation into peptides. Key features include final global acidolytic protective group removal, as well as full compatibility with standard Fmoc solid-phase peptide synthesis (SPPS). ...

Click chemistry was used to introduce moieties as sterically demanding as monosaccharides into the Yaa position of collagen model peptides. The effect of different triazolyl derivatives as well as the configuration of the functionalized proline residue on the thermal stability of the collagen triple helices was examined.

As a peptide hormone, CLV3 restricts the stem cell number in shoot apical meristem (SAM) by interacting with CLV1/CLV2/CRN/RPK2 receptor complexes. To elucidate how the function of the CLV3 peptide in SAM maintenance is established at the amino acid (AA) level, alanine substitutions were performed by introducing point mutations to ...

ABSTRACT: BACKGROUND: HCV is prevalent throughout the world. It is a major cause of chronic liver disease. There is no effective vaccine and the most common therapy, based on Peginterferon, has a success rate of ~50%. The mechanisms underlying viral resistance have not been elucidated but it has been suggested ...

Nature has evolved objects with desired functionality using commonly found materials. Nature capitalizes on hierarchical structures to achieve functionality. The understanding of the functions provided by objects and processes found in nature can guide us to produce nanomaterials, nanodevices, and processes with desirable functionality. Various natural objects which provide functionality ...

The intestinal epithelial barrier is indispensable to our immune system. Defects in this barrier function have been observed in intestinal disorders such as inflammatory bowel diseases, food allergies, and celiac diseases. Therefore, the modulation of the barrier function is currently viewed as a potentially positive pharmacological outcome. This review describes ...

SP-B(CTERM) is a cationic amphipathic helical peptide and functional fragment composed of residues 63 to 78 of surfactant protein B (SP-B). Static oriented and magic angle spinning solid state NMR, along with molecular dynamics simulation was used to investigate its structure, orientation, and depth in lipid bilayers of several compositions, ...

A first step toward predicting the structure of a protein is to determine its secondary structure. The secondary structure information is generally used as starting point to solve protein crystal structures. In the present study, a machine learning approach based on a complete set of two-class scoring functions was used. ...

Aryl thiolates have unique reactive, redox, electronic, and spectroscopic properties. A practical approach to synthesize peptides containing thiophenylalanine has been developed via a novel Cu(I)-mediated cross-coupling reaction between thiolacetic acid and iodophenylalanine-containing peptides in the solid phase. This approach is compatible with all canonical proteinogenic functional groups, providing general access ...

We introduce PMF*, a novel potential of mean force (PMF) for the Ramachandran ϕ/Ψ dihedral plot of the 20 standard amino acids and assess its relevance to the conformation of polypeptides by scoring structures in the protein data bank and decoy datasets. The new energy function is a linear combination ...

The DJ-1 superfamily (DJ-1/ThiJ/PfpI superfamily) is distributed across all three kingdoms of life. These proteins are involved in a highly diverse range of cellular functions, including chaperone and protease activity. DJ-1 proteins usually form dimers or hexamers in vivo and show at least four different binding orientations via distinct interface ...

A common site in the constant region (Fc) of immunoglobulins is recognized by host receptors and is a frequent target of proteins expressed by pathogens. This site is located at the junction of two constant domains in the antibody heavy chains and produces a large shallow cavity formed by loops ...

An important goal in the development of highly functional organic materials is to design self-assembling molecules that can reproducibly display chemical signals across length scales. Within the biomedical field, biomolecules are highly attractive candidates to serve as bioactive building blocks for the next generation of biomaterials. The peptide amphiphiles (PAs) ...

CD44 and RHAMM are two extracellar matrix receptors whose principle ligand is the polysaccharide hyaluronan (HA). Both proteins are involved in wound repair and their aberrant regulation contributes to a variety of diseases including arthritis and cancer. Over the past decade, a number of peptide-based therapeutics that block the binding ...

Peptide nucleic acid (PNA) is a non-cyclic pseudopeptide-nucleic acid structural mimic with promising applications within diagnostics and drug discovery. This review focuses on metal complex derivatives of PNA. Metal ions and their complexes display unique physical and chemical properties and offer the opportunity to introduce new labels and probes for ...

The crustacean Hyperglycemic Hormone (cHH) is present in many decapods in different isoforms, whose specific biological functions are still poorly understood. Here we report on the first chemical synthesis of three distinct isoforms of the cHH of Astacus leptodactylus carried out by solid phase peptide synthesis coupled to native chemical ...

Nucleophilic imine additions with vinyl organometallics have developed into efficient, high yielding, and robust methodologies to generate structurally diverse allylic amines. We have used the hydrozirconation-transmetalation-imine addition protocol in the synthesis of allylic amine intermediates for peptide bond isosteres, phosphatase inhibitors, and mitochondria-targeted peptide mimetics. The gramicidin S-derived XJB-5-131 and ...

In this study, a new functionalized peptide RLN was designed containing the bioactive motif link N, the amino terminal peptide of link protein. A link N nanofiber scaffold (LN-NS) was self-assembled by mixing peptide solution of RLN and RADA16. The characterization of LN-NS was tested using atomic force microscopy (AFM). ...

The present paper reports on a generic strategy to specifically introduce functionalities or functions to surfaces of inorganic nanoparticles by exploiting tailor-made peptide-adhesion domains. Suitable peptide sequences could be selected for specific inorganic particles by biocombinatorial means of phage display. The selected peptides exhibit sequence-specific adhesion onto the particle surfaces ...

In recent years, gold nanoparticles have been increasingly utilized as a promising material for biomedical analysis. We report here for the first time the synthesis of ultrasmall gold nanoparticles with core diameter of 1.2 nm functionalized with hydrazide groups and their use in isolation/enrichment of N-glycosylated peptides. Hydrazide-functionalized gold nanoparticles ...

The tertiary structures of functional RNA molecules remain difficult to decipher. A new generation of automated RNA structure prediction methods may help address these challenges but have not yet been experimentally validated. Here we apply four prediction tools to a remarkable class of double glycine riboswitches that can bind two ...

Mutations in the polypeptide sequence that forms the core structure of amyloid fibrils are known to impact on fibril assembly and stability, but the effect of changes on noncore residues, particularly relating to functionalized fibrils where the fibril core is preserved, has not been systematically examined. In this study, the ...

The initiation and progression of Alzheimer's disease is coupled to the oligo- and polymerization of amyloid peptides in the brain. Amyloid like aggregates of protein domains were found practically independent of their primary sequences. Thus, the driving force of the transformation from the original to a disordered amyloid fold is ...

The poly(ADP-ribose)polymerases Tankyrase 1/2 (TNKS/TNKS2) catalyze the covalent linkage of ADP-ribose polymer chains onto target proteins, regulating their ubiquitylation, stability, and function. Dysregulation of substrate recognition by Tankyrases underlies the human disease cherubism. Tankyrases recruit specific motifs (often called RxxPDG "hexapeptides") in their substrates via an N-terminal region of ankyrin ...

Almost 90 years have passed since Alexander Fleming discovered the antimicrobial activity of lysozyme, the first natural antibiotic isolated from our body. Since then, various types of molecules with antibiotic activity have been isolated from animals, insects, plants, and bacteria, and their use has revolutionized clinical medicine. So far, more ...

We present a Molecular Dynamics study of the binding process of peptide A3 (AYSSGAPPMPPF) and other similar peptides onto gold surfaces, and identify the functions of many amino acids. Our results provide a clear picture of the separate regimes present in the binding process: diffusion, anchoring, crawling and binding. Moreover, ...

Functional amyloids have been identified in a wide range of organisms, taking on a variety of biological roles, and being controlled by remarkable mechanisms of directed assembly. Here we report that amyloid fibrils constitute the ribs of the buoyancy organelles of Anabaena flos-aquae. The walls of these gas-filled vesicles are ...

Cysteine (Cys) is much different from other common amino acids in proteins. Being one of the least abundant residues, Cys is often observed in functional sites in proteins. This residue is reactive, polarizable, redox-active, has high affinity for metals, and is particularly responsive to the local environment. A better understanding ...

Most self-replicating peptide systems are made of α-helix forming sequences. However, it has been postulated that shorter and simpler peptides may also serve as templates for replication when arranged into well-defined structures. We describe here the design and characterization of new peptides that form soluble β-sheet aggregates that serve to ...

In addition to the core structure conserved in all troponin I isoforms, cardiac troponin I (cTnI) has an ∼30 amino acids NH(2)-terminal extension. This peptide segment is a heart-specific regulatory structure containing two Ser residues that are substrates of PKA. Under β-adrenergic regulation, phosphorylation of cTnI in the NH(2)-terminal extension ...

Chemoreceptors transmit signals from the environment to the flagellar motors via a histidine kinase that controls the phosphorylation level of the effector protein CheY. The cytoplasmic domain of chemoreceptors is strongly conserved and consists of a long alpha-helical hairpin that forms, in the dimer, a coiled-coil four-helix bundle. Changes in ...

The amino terminal domain (ATD) of ionotropic glutamate receptor (iGluR) subunits resides at the extracellular region distal to the membrane. The ATD is structurally and functionally the most divergent region of the iGluR subunits. Structural studies on full-length GluA2 and the ATDs from three iGluR subfamilies have shed light on ...

The elucidation of the whole genome of the nematode Caenorhabditis elegans allowed for the identification of ortholog genes belonging to the pigment dispersing hormone/factor (PDH/PDF) peptide family. Members of this peptide family are known from crustaceans, insects and nematodes and seem to exist exclusively in ecdysozoans where they play a ...

Cruciferin is the major storage protein in Brassicaceae family oilseeds. The predominant cruciferin isoforms in Arabidopsis thaliana were investigated using homology modelling (HM) for their molecular structures and functional properties. The structure of Brassica napus procruciferin was used as the template for HM to determine the molecular structures and hypervariable ...

von Willebrand factor (VWF) is a long plasma protein that contains many domains and each domain has its own function. VWF exists in a multimeric form and performs varieties of functions in the human body, including thrombus formation and blood coagulation. The crystal structures of three subdomains are known, and, ...

Life-threatening infectious diseases are on their way to cause a worldwide crisis, as treating them effectively is becoming increasingly difficult due to the emergence of antibiotic resistant strains. Antimicrobial peptides (AMPs) form an ancient type of innate immunity found universally in all living organisms, providing a principal first-line of defense ...

The doubly-protonated peptides Ala-Ala-Xaa-Ala-Ala-Ala-Arg show extensive loss of H(2)O when Xaa = Ser or Thr. Using quasi-MS(3) techniques the fragmentation reactions of the [M + 2H - H(2)O](+2) ions have been studied in detail. For both Ser and Thr, the [M + 2H - H(2)O](+2) ions show three primary fragmentation reactions, elimination of CH(3)CH = NH, elimination of ...

Dsb proteins play important roles in bacterial pathogenicity. To better understand the role of Dsb proteins in Helicobacter pylori, we have structurally and functionally characterized H. pylori DsbG (HP0231). The monomer consists of two domains connected by a helical linker. Two monomers associate to form a V-shaped dimer. The monomeric ...

Although amyloid fibrils are generally considered to be causative or contributing agents in amyloid diseases, several amyloid fibrils are also believed to have biological functions. Among these are fibrils formed by Pmel17 within melanosomes, which act as a template for melanin deposition. We use solid-state NMR to show that the ...

The brains of Alzheimer's disease patients show an increased number of senile plaques compared with normal patients. The major component of the plaques is the β-amyloid peptide, a cleavage product of the amyloid precursor protein (APP). Although the processing of APP has been well-described, the physiological functions of APP and ...

The richly structured neuroendocrine control of the heart in health and disease requires, in addition to the autonomic nervous outflow, the essential contribute of various and often interacting humoral peptides (e.g. natriuretic peptides, Chromogranin-A-derived fragments, etc). In many cases, these molecules also influence the activity of other organ systems, including ...

This review attempts to provide an updated compilation of studies reported in the literature pertaining to production of nanocarriers encasing peptides and/or proteins, in a way that helps the reader direct a bibliographic search and develop an integrated perspective of the subject. Highlights are given to bioactive proteins and peptides, ...

In all organisms tRNAs play the essential role of connecting the genetic information found in DNA with the protein synthesis machinery ensuring fidelity during translation. Following transcription tRNAs undergo a number of processing events including numerous post-transcriptional modifications that render a tRNA molecule fully functional. The effects of some modifications ...

Unc13/Munc13s play a crucial function in neurotransmitter release through their MUN domain, which mediates the transition from the Syntaxin-1/Munc18-1 complex to the SNARE complex. The MUN domain was suggested to be related to tethering factors, but no MUN-domain structure is available to experimentally validate this notion and address key unresolved questions ...

The synthesis of novel chiral coumarins functionalized with proteinogenic amino acid side chains via N-protected γ-amino-β-keto esters and their incorporation into the cell permeable HIV-1 TAT peptide through the modified solid phase peptide synthesis are described.