Target-Templated Construction of Functional Proteomimetics Using Photo-Foldamer Libraries.

Current methods for proteomimetic engineering rely on structure-based design. Here we describe a design strategy that allows the construction of proteomimetics against challenging targets without a priori characterization of the target surface. Our approach employs (i) a 100-membered photoreactive foldamer library, the members of which act as local surface mimetics, and (ii) the subsequent affinity maturation of the primary hits using systems chemistry.

Same same, but different: exploring the enigmatic role of the pituitary adenylate cyclase-activating polypeptide (PACAP) in invertebrate physiology.

Evidence has been accumulating that elements of the vertebrate pituitary adenylate cyclase-activating polypeptide (PACAP) system are missing in non-chordate genomes, which is at odds with the partial sequence-, immunohistochemical-, and physiological data in the literature. Multilevel experiments were performed on the great pond snail (Lymnaea stagnalis) to explore the role of PACAP in invertebrates. Screening of neuronal transcriptome and genome data did not reveal homologs to the elements of vertebrate PACAP system.

Liquid Chromatographic Enantioseparation of Newly Synthesized Fluorinated Tryptophan Analogs Applying Macrocyclic Glycopeptides-Based Chiral Stationary Phases Utilizing Core-Shell Particles.

Due to the favorable features obtained through the incorporation of fluorine atom(s), fluorinated drugs are a group with emerging pharmaceutical importance. As their commercial availability is still very limited, to expand the range of possible candidates, new fluorinated tryptophan analogs were synthesized. Control of enantiopurity during the synthesis procedure requires that highly efficient enantioseparation methods be available.

Rational Design of Antifungal Peptides Based on the γ-Core Motif of a () Antifungal Protein to Improve Structural Integrity, Efficacy, and Spectrum.

Antifungal peptides offer promising alternative compounds for the treatment of fungal infections, for which new antifungal compounds are urgently needed. Constant and broad antifungal spectra of these peptides play essential roles in their reliable therapeutic application. It has been observed that rationally designed peptides using the evolutionarily conserved γ-core region (GXC-X-C) of an antifungal protein from () highly inhibit the growth of fungi.

Proline Isomerization in Intrinsically Disordered Proteins and Peptides.

Background: Intrinsically disordered proteins and protein regions (IDPs/IDRs) are important in diverse biological processes. Lacking a stable secondary structure, they display an ensemble of conformations. One factor contributing to this conformational heterogeneity is the proline isomerization.

Hard nut to crack: Solving the disulfide linkage pattern of the Neosartorya (Aspergillus) fischeri antifungal protein 2.

As a consequence of the fast resistance spreading, a limited number of drugs are available to treat fungal infections. Therefore, there is an urgent need to develop new antifungal treatment strategies. The features of a disulfide bond-stabilized antifungal protein, NFAP2 secreted by the mold Neosartorya (Aspergillus) fischeri render it to be a promising template for future protein-based antifungal drug design, which requires knowledge about the native disulfide linkage pattern as it is one of the prerequisites for biological activity.

Confirmation of the Disulfide Connectivity and Strategies for Chemical Synthesis of the Four-Disulfide-Bond-Stabilized Antifungal Protein, AFP.

Emerging fungal infections require new, more efficient antifungal agents and therapies. AFP, a protein from with four disulfide bonds, is a promising candidate because it selectively inhibits the growth of filamentous fungi. In this work, the reduced form of AFP was prepared using native chemical ligation.

Enhanced Antibacterial Activity of Substituted Derivatives of NCR169C Peptide.

in symbiosis with its rhizobial bacterium partner produces more than 700 nodule-specific cysteine-rich (NCR) peptides with diverse physicochemical properties. Most of the cationic NCR peptides have antimicrobial activity and the potential to tackle antimicrobial resistance with their novel modes of action. This work focuses on the antibacterial activity of the NCR169 peptide derivatives as we previously demonstrated that the C-terminal sequence of NCR169 (NCR169C) has antifungal activity, affecting the viability, morphology, and biofilm formation of various species.

Synthesis of the extracellular domain of GLP-1R by chemical and biotechnological approaches.

The extracellular domain of the glucagon-like peptide-1 receptor, GLP-1R, is responsible for the binding of GLP-1, and a handful of additional agonists (such as exenatide, lixisenatide, and liraglutide) used daily for treating type II diabetes mellitus. Lead discovery and optimization, however, require binding studies, which, in turn, necessitate the total synthesis of GLP-1R, comprising 108 residues. A protein domain of 10-15 kDa size could be obtained either by expression in or by ligating solid-phase peptide synthesis (SPPS)-made fragments.

Preparation of 3--, 5-- and -palmitoyl derivatives of fumonisin B toxin and their characterisation with NMR and LC-HRMS methods.

We have previously published six esterified -acyl (EFB1) and three -acyl fumonisin B derivatives extracted from rice cultures inoculated with , amongst these the identification of -palmitoyl-FB1 has been clearly established in a spiking experiment. At that time, it was assumed that as in the case of -acyl-FB1 derivatives, linoleic-, oleic- or palmitic acid esterify through the OH group on the 3C or 5C atom of the carbon chain of the fumonisins. In our most recent experiments, we have synthetically acylated the FB1 toxin and subsequently purified 3--palmitoyl- and 5--palmitoyl-FB1 toxins in addition to the -palmitoyl-FB1 toxin.

Legume Plant Peptides as Sources of Novel Antimicrobial Molecules Against Human Pathogens.

Antimicrobial peptides are prominent components of the plant immune system acting against a wide variety of pathogens. Legume plants from the inverted repeat lacking clade (IRLC) have evolved a unique gene family encoding nodule-specific cysteine-rich NCR peptides acting in the symbiotic cells of root nodules, where they convert their bacterial endosymbionts into non-cultivable, polyploid nitrogen-fixing cells. NCRs are usually 30-50 amino acids long peptides having a characteristic pattern of 4 or 6 cysteines and highly divergent amino acid composition.

Rationally Designed Antimicrobial Peptides Are Potential Tools to Combat Devastating Bacteria and Fungi.

The introduction of the first antibiotic (penicillin) by Sir Alexander Fleming in 1928 was a huge milestone in the treatment of infectious diseases [...

Incorporation of Oxidized Phenylalanine Derivatives into Insulin Signaling Relevant Proteins May Link Oxidative Stress to Signaling Conditions Underlying Chronic Insulin Resistance.

A link between oxidative stress and insulin resistance has been suggested. Hydroxyl free radicals are known to be able to convert phenylalanine (Phe) into the non-physiological tyrosine isoforms ortho- and meta-tyrosine (o-Tyr, m-Tyr). The aim of our study was to examine the role of o-Tyr and m-Tyr in the development of insulin resistance.

The combination of () antifungal proteins with rationally designed γ-core peptide derivatives is effective for plant and crop protection.

Unlabelled: Plant pathogenic fungi are responsible for enormous crop losses worldwide. Overcoming this problem is challenging as these fungi can be highly resistant to approved chemical fungicides. There is thus a need to develop and introduce fundamentally new plant and crop protection strategies for sustainable agricultural production.

sVmKTx, a transcriptome analysis-based synthetic peptide analogue of Vm24, inhibits Kv1.3 channels of human T cells with improved selectivity.

Kv1.3 K channels play a central role in the regulation of T cell activation and Ca signaling under physiological and pathophysiological conditions. Peptide toxins targeting Kv1.

Novel Lysine-Rich Delivery Peptides of Plant Origin ERD and Human S100: The Effect of Carboxyfluorescein Conjugation, Influence of Aromatic and Proline Residues, Cellular Internalization, and Penetration Ability.

The need for novel drug delivery peptides is an important issue of the modern pharmaceutical research. Here, we test K-rich peptides from plant dehydrin ERD14 (ERD-A, ERD-B, and ERD-C) and the C-terminal CPP-resembling region of S100A4 (S100) using the 5(6)-carboxyfluorescein (Cf) tag at the N-terminus. Via a combined pH-dependent NMR and fluorescence study, we analyze the effect of the Cf conjugation/modification on the structural behavior, separately investigating the (5)-Cf and (6)-Cf forms.

Functional characterization and related evolutionary implications of invertebrate gonadotropin-releasing hormone/corazonin in a well-established model species.

In vertebrates, gonadotropin-releasing hormone (GnRH) peptide is the central mediator of reproduction. Homologous peptides have previously also been identified in molluscan species. However, emerging evidence suggests that these molecules might serve diverse regulatory functions and proposes to consider them as corazonin (CRZ).

Symbiotic NCR Peptide Fragments Affect the Viability, Morphology and Biofilm Formation of Species.

The increasing rate of fungal infections causes global problems not only in human healthcare but agriculture as well. To combat fungal pathogens limited numbers of antifungal agents are available therefore alternative drugs are needed. Antimicrobial peptides are potent candidates because of their broad activity spectrum and their diverse mode of actions.

Solution Structure, Dynamics, and New Antifungal Aspects of the Cysteine-Rich Miniprotein PAFC.

The genome of Q176 contains a gene coding for the 88-amino-acid (aa)-long glycine- and cysteine-rich antifungal protein C (PAFC). After maturation, the secreted antifungal miniprotein (MP) comprises 64 aa and shares 80% aa identity with the bubble protein (BP) from , which has a published X-ray structure. Our team expressed isotope (N, C)-labeled, recombinant PAFC in high yields, which allowed us to determine the solution structure and molecular dynamics by nuclear magnetic resonance (NMR) experiments.

The Antifungal Protein 2 (NFAP2): A New Potential Weapon against Multidrug-Resistant Biofilms.

is a potential multidrug-resistant pathogen able to persist on indwelling devices as a biofilm, which serve as a source of catheter-associated infections. antifungal protein 2 (NFAP2) is a cysteine-rich, cationic protein with potent anti- activity. We studied the in vitro activity of NFAP2 alone and in combination with fluconazole, amphotericin B, anidulafungin, caspofungin, and micafungin against biofilms.

The Q176 Antimicrobial Protein PAFC Effectively Inhibits the Growth of the Opportunistic Human Pathogen .

Small, cysteine-rich and cationic antimicrobial proteins (AMPs) from filamentous ascomycetes promise treatment alternatives to licensed antifungal drugs. In this study, we characterized the Q176 antifungal protein C (PAFC), which is phylogenetically distinct to the other two antifungal proteins, PAF and PAFB, that are expressed by this biotechnologically important ascomycete. PAFC is secreted into the culture broth and is co-expressed with PAF and PAFB in the exudates of surface cultures.

Biofungicidal Potential of () Antifungal Protein NFAP and Novel Synthetic γ-Core Peptides.

Because of enormous crop losses worldwide due to pesticide-resistant plant pathogenic fungi, there is an increasing demand for the development of novel antifungal strategies in agriculture. Antifungal proteins (APs) and peptides are considered potential biofungicides; however, several factors limit their direct agricultural application, such as the high cost of production, narrow antifungal spectrum, and detrimental effects to plant development and human/animal health. This study evaluated the safety of the application of APs and peptides from the ascomycete as crop preservatives.

Stability Test of PACAP in Eye Drops.

PACAP is a neuropeptide with widespread distribution and diverse biological functions. It has strong cytoprotective effects mediated mainly through specific PAC1 receptors. Experimental data show protective effects of PACAP in the retina and cornea in several pathological conditions.

The potential use of the Penicillium chrysogenum antifungal protein PAF, the designed variant PAF and its γ-core peptide Pγ in plant protection.

The prevention of enormous crop losses caused by pesticide-resistant fungi is a serious challenge in agriculture. Application of alternative fungicides, such as antifungal proteins and peptides, provides a promising basis to overcome this problem; however, their direct use in fields suffers limitations, such as high cost of production, low stability, narrow antifungal spectrum and toxicity on plant or mammalian cells. Recently, we demonstrated that a Penicillium chrysogenum-based expression system provides a feasible tool for economic production of P.

Potent Chimeric Antimicrobial Derivatives of the NCR247 Symbiotic Peptide.

In Rhizobium-legume symbiosis, the bacteria are converted into nitrogen-fixing bacteroids. In many legume species, differentiation of the endosymbiotic bacteria is irreversible, culminating in definitive loss of their cell division ability. This terminal differentiation is mediated by plant peptides produced in the symbiotic cells.