ABSTRACT
Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 versus N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza.
Subject(s)
Antiviral Agents/chemistry , Benzoic Acid/chemistry , Influenza A virus/enzymology , Neuraminidase/antagonists & inhibitors , Pyrrolidinones/chemistry , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Benzoic Acid/chemical synthesis , Benzoic Acid/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Hydrophobic and Hydrophilic Interactions , Influenza A Virus, H1N1 Subtype/drug effects , Influenza A Virus, H3N2 Subtype/drug effects , Influenza A virus/drug effects , Neuraminidase/metabolism , Structure-Activity RelationshipABSTRACT
Chemical cross-linking combined with mass spectrometry (MS) has been used to elucidate protein structures and protein-protein interactions. However, heterogeneity of the samples and the relatively low abundance of cross-linked peptides make this approach challenging. As an effort to overcome this hurdle, we have synthesized lysine-reactive homobifunctional cross-linkers with the biotin in the middle of the linker and used them to enrich cross-linked peptides. The reaction of biotin-tagged cross-linkers with purified HIV-1 CA resulted in the formation of hanging and intramolecular cross-links. The peptides modified with biotinylated cross-linkers were effectively enriched and recovered using a streptavidin-coated plate and MS-friendly buffers. The enrichment of modified peptides and removal of the dominantly unmodified peptides simplify mass spectra and their analyses. The combination of the high mass accuracy of Fourier transform ion cyclotron resonance (FT-ICR) MS and the tandem mass spectrometric (MS/MS) capability of the linear ion trap allows us to unambiguously identify the cross-linking sites and additional modification, such as oxidation.
Subject(s)
Biotin/chemistry , Cross-Linking Reagents/chemistry , Tandem Mass Spectrometry/methods , Biotin/chemical synthesis , Capsid Proteins/chemistry , Capsid Proteins/metabolism , Cross-Linking Reagents/chemical synthesis , HIV-1/chemistry , HIV-1/metabolism , Spectroscopy, Fourier Transform InfraredABSTRACT
A series of aromatic aminoketones were synthesized by Mannich reaction. Structures of these compounds were confirmed by 1H NMR, MS and HRMS or element analysis. Pharmacological screening showed that most target compounds inhibited the release of beta-glucuronidase in polymorphonuclear leucocytes by PAF (platelet activating factor) and compounds MA12, MA13, MA18, MA21 and MA33 were more active. The study suggests that target compounds are potential PAF receptor antagonists and their anti-inflammatory activities are due to the inhibition of release of lysosomal enzyme.
Subject(s)
Anti-Inflammatory Agents/chemical synthesis , Anti-Inflammatory Agents/pharmacology , Ketones/chemical synthesis , Ketones/pharmacology , Platelet Membrane Glycoproteins/antagonists & inhibitors , Receptors, G-Protein-Coupled/antagonists & inhibitors , Animals , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/therapeutic use , Arthritis, Rheumatoid/drug therapy , Glucuronidase/metabolism , Ketones/chemistry , Ketones/therapeutic use , Macrophages, Peritoneal/metabolism , Mice , Neutrophils/enzymology , Rats , Structure-Activity Relationship , Tumor Necrosis Factor-alpha/biosynthesisABSTRACT
Tethered dimers incorporating natural alpha-amino acid end groups were synthesized, including examples in which the previously reported esterase-sensitive ester linker was replaced with more stable amide or ether linkers. These compounds remained effective both as inhibitors of NAD synthetase and as potent antibacterial agents for Gram-positive strains. Studies on nonspecific effects, including detergent properties and promiscuous inhibition, suggested little contribution to observed activities.