Complete non-proline backbone resonance assignments of the S. aureus neutrophil serine protease inhibitor, EapH1.

The S. aureus extracellular adherence protein (Eap) and its homologs, EapH1 and EapH2, serve roles in evasion of the human innate immune system. EapH1 binds with high-affinity and inhibits the neutrophil azurophilic granule proteases neutrophil elastase, cathepsin-G and proteinase-3.

Ecdysis triggering hormone peptide in the African malaria mosquito Anopheles gambiae: The peptide structure for receptor activation.

Infections by mosquito-borne diseases represent one of the leading causes of death in third world countries. The rapid progression of resistance to conventional insecticide causes a significant threat to the highly efficient preventive methods currently in place. Insect neuropeptidergic system offers potential targets to control the insect vectors.

1H, 15N, and 13C backbone resonance assignments of the C4b-binding region from the S. aureus extracellular adherence protein.

The Extracellular Adherence Protein (Eap) from Staphylococcus aureus is a potent inhibitor of the classical and lectin pathways of the complement system. Previous studies have shown that Eap binds with nanomolar affinity to complement component C4b and prevents C4b binding the pro-protease, C2, thereby inhibiting formation of the pro-C3 convertase shared by the classical and lectin pathways (Woehl et al. in J Immunol 193:6161-6171, 2014).

Dietary flavonoid fisetin binds human SUMO1 and blocks sumoylation of p53.

Flavonoids are plant-derived compounds that occur abundantly in fruits and vegetables and have been shown to possess potent anti-cancer, antioxidant, and anti-inflammatory properties. However, their direct targets and molecular mechanism of action are not well characterized, hampering exploitation of the beneficial properties of flavonoids for drug development. Small ubiquitin-related modifier 1 (SUMO1) is attached to target proteins as part of a post-translational modification system implicated in a myriad of cellular processes from nuclear trafficking to transcriptional regulation.

Backbone resonance assignments of innate immune evasion protein EapH2 from the S. aureus.

Staphylococcus aureus is a ubiquitous and persistent pathogen of humans and livestock. The bacterium disrupts the host's innate immune system's ability to recognize and clear bacteria with optimal efficiency by expressing a wide variety of virulence proteins. Two single domain protein homologs (EapH1, EapH2) of the extracellular adherence protein (Eap) have been reported.

H, N, and C resonance assignments of the third domain from the S. aureus innate immune evasion protein Eap.

Staphylococcus aureus is a widespread and persistent pathogen of humans and livestock. The bacterium expresses a wide variety of virulence proteins, many of which serve to disrupt the host's innate immune system from recognizing and clearing bacteria with optimal efficiency. The extracellular adherence protein (Eap) is a multidomain protein that participates in various protein-protein interactions that inhibit the innate immune response, including both the complement system (Woehl et al in J Immunol 193:6161-6171, 2014) and Neutrophil Serine Proteases (NSPs) (Stapels et al in Proc Natl Acad Sci USA 111:13187-13192, 2014).

A structurally dynamic N-terminal region drives function of the staphylococcal peroxidase inhibitor (SPIN).

The heme-containing enzyme myeloperoxidase (MPO) is critical for optimal antimicrobial activity of human neutrophils. We recently discovered that the bacterium expresses a novel immune evasion protein, called SPIN, that binds tightly to MPO, inhibits MPO activity, and contributes to bacterial survival following phagocytosis. A co-crystal structure of SPIN bound to MPO suggested that SPIN blocks substrate access to the catalytic heme by inserting an N-terminal β-hairpin into the MPO active-site channel.

Backbone and side-chain H, N, and C resonance assignments of a novel Staphylococcal inhibitor of myeloperoxidase.

The bacterium Staphylococcus aureus produces an array of anti-inflammatory molecules that prevent the innate immune system from recognizing it as a pathogen and clearing it from the host. In the acute phase of inflammation, our immune system relies on neutrophils to clear invading bacteria. Recently, novel classes of secreted proteins from S.

Solution Structure and Expression Profile of an Insect Cytokine: Manduca sexta Stress Response Peptide-2.

Manduca sexta stress response peptide-2 (SRP2) is predicted to be a 25-residue peptide (FGVKDGKCPSGRVRRLGICVPDDDY), which may function as an insect cytokine to regulate immune responses. Produced as an inactive precursor, endogenous proSRP2 is probably converted to active SRP2 by limited proteolysis in response to invading pathogens, along with prophenoloxidase and pro-Spätzle activation. In addition to immunity, SRP2 may control head morphogenesis or other developmental processes in the lepidopteran insect.

Membrane Interacting Peptides: A Review.

Membrane interacting peptides of natural or synthetic origins serve a variety of biological purposes. They have been extensively studied for their involvement in immunity, diseases, and for their potential as medical therapeutics and research tools. In this review membrane interacting peptides are categorized into four groups according to their function: antimicrobial peptides, cell-penetrating peptides, channel forming peptides and amyloid peptides.

(1)H, (15)N, and (13)C resonance assignments of Staphylococcus aureus extracellular adherence protein domain 4.

The pathogenic bacterium Staphylococcus aureus has evolved to actively evade many aspects of the human innate immune system by expressing a series of secreted inhibitory proteins. Among these, the extracellular adherence protein (Eap) has been shown to inhibit the classical and lectin pathways of the complement system. By binding to complement component C4b, Eap is able to inhibit formation of the CP/LP C3 pro-convertase.

Lignins of bioenergy crops: a review?

Lignin provides structural support, a mechanical barrier against microbial infestation and facilitates movement of water inside plant systems. It is the second most abundant natural polymer in the terrestrial environments and possesses unique routes for the production of bulk and specialty chemicals with aromatic/phenolic skeletons. The commercial applications of lignin are limited and it is often recognized for its negative impact on the biochemical conversion of lignocellulosic biomass to fuels and chemicals.

Structural transformation and physical properties of a hydrogel-forming peptide studied by NMR, transmission electron microscopy, and dynamic rheometer.

Peptide-based hydrogels are attractive biological materials. Study of their self-assembly pathways from their monomer structures is important not only for undertaking the rational design of peptide-based materials, but also for understanding their biological functions and the mechanism of many human diseases relative to protein aggregation. In this work, we have monitored the conformation, morphological, and mechanical properties of a hydrogel-forming peptide during hydrogelation in different dimethylsulfoxide (DMSO)/H(2)O solutions.

Morphology and structural properties of pH-responsive amphiphilic peptides.

Protein nanomaterials at the peptide level have shown great potential for medical applications. Peptides change their morphological conformation because of changes in self-assembly properties when they are exposed to changes in solvent composition or pH. Two 15-residue peptide sequences, KhK (KKKFLIVIGSIIKKK) and Alternating Kh (KFLKKIVKIGKKSII), were designed for the purpose of determining the role of peptide sequence on solution morphology and conformation.

Structural characterization of two pore-forming peptides: consequences of introducing a C-terminal tryptophan.

Synthetic channel-forming peptides that can restore chloride conductance across epithelial membranes could provide a novel treatment of channelopathies such as cystic fibrosis. Among a series of 22-residue peptides derived from the second transmembrane segment of the glycine receptor alpha(1)-subunit (M2GlyR), p22-S22W (KKKKP ARVGL GITTV LTMTT QW) is particularly promising with robust membrane insertion and assembly. The concentration to reach one-half maximal short circuit current is reduced to 45 +/- 6 microM from that of 210 +/- 70 microM of peptide p22 (KKKKP ARVGL GITTV LTMTT QS).

The central kink region of fowlicidin-2, an alpha-helical host defense peptide, is critically involved in bacterial killing and endotoxin neutralization.

Fowlicidins are a group of newly identified chicken cathelicidin host defense peptides. We have shown that the putatively mature fowlicidin-2 of 31 amino acid residues possesses potent antibacterial and lipopolysaccharide (LPS)- neutralizing activities, but with a noticeable toxicity to mammalian cells. As a first step in exploring the structure-activity relationships of fowlicidin-2, in this study we determined its tertiary structure by nuclear magnetic resonance spectroscopy.