ABSTRACT
Secretory phospholipase A2 (sPLA2) and matrix metallopreoteinases (MMPs) are key enzymes involved in rheumatoid arthritis (RA), and their modulation thus represents a potential therapeutic option. On the basis of Escherichia coli radioassay, synthetic peptides were designed and screened for sPLA2 inhibition. The linear peptide, 10f (PIP-18), inhibited the recombinant human synovial sPLA2 activity with an IC50 of 1.19 microM. Not only did the peptide interfere with the function of sPLA2, but it also appeared to inhibit mRNA expression of sPLA2 and various MMPs in IL-1beta-stimulated RA synovial fibroblast (RASF) cultures and thereby the production of the corresponding proteins (>80% inhibition). Nuclear magnetic resonance (NMR), modeling, and docking studies indicate that in solution the peptide exhibits a beta-turn at residues Trp-Asp-Gly-Val and possibly binds to the hydrophobic channel of sPLA2. The results strongly suggest that the modulatory action of peptide 10f may play a major role in counteracting the development of RA.
Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/chemical synthesis , Models, Molecular , Peptides/chemical synthesis , Phospholipases A2, Secretory/antagonists & inhibitors , Phospholipases A2, Secretory/chemistry , Animals , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Arthritis, Rheumatoid/enzymology , Cells, Cultured , Circular Dichroism , Fibroblasts/drug effects , Fibroblasts/enzymology , Gene Expression/drug effects , Humans , Magnetic Resonance Spectroscopy , Matrix Metalloproteinases/biosynthesis , Oligopeptides/chemical synthesis , Oligopeptides/chemistry , Oligopeptides/pharmacology , Peptides/chemistry , Peptides/pharmacology , Peptides, Cyclic/chemical synthesis , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Phospholipases A2, Secretory/biosynthesis , Protein Binding , Protein Conformation , Rabbits , Solutions , Structure-Activity Relationship , Synovial Fluid/cytologyABSTRACT
Adhesion molecules participate in many stages of immune response; they regulate leukocyte circulation, lymphoid cell homing to tissues and inflammatory sites, migration across endothelial cells and T-cell stimulation. During T-cell immune response, adhesion molecules form a specialized junction between T-cell and the antigen presenting cell. Thus, many researchers have focused their attention on targeting adhesion molecules for developing therapeutic agents. Most of these efforts are intended to develop drugs for autoimmune and inflammatory diseases. Therapeutic agents like efalizumab and alefacept have been approved by the FDA for the treatment of inflammatory autoimmune diseases. This review focuses on some of the basic aspects and importance of adhesion molecules, recent understanding of the structure of adhesion molecules, and the targeted therapeutic agents.
Subject(s)
Cell Adhesion Molecules , Drug Delivery Systems/methods , Drug Design , T-Lymphocytes , Amino Acid Sequence , Animals , Cell Adhesion Molecules/chemistry , Cell Adhesion Molecules/genetics , Humans , Molecular Sequence Data , Protein Structure, Secondary/physiology , T-Lymphocytes/immunologyABSTRACT
Neuropeptide Y (NPY), receptors belong to the G-protein coupled receptor superfamily. NPY mediates several physiological responses, such as blood pressure, food intake, sedation. These actions of NPY are mediated by six receptor subtypes denoted as Y1-Y5 and y6. Modeling of receptor subtypes and binding site identification is an important step in developing new therapeutic agents. We have attempted to model the three NPY receptor types, Y1, Y4, and Y5 using homology modeling and threading methods. The models are consistent with previously reported experimental evidence. To understand the interaction and selectivity of NPY analogues with different neuropeptide receptors, docking studies of two neuropeptide analogues (BVD10 and BVD15) with receptors Y1 and Y4 were carried out. Results of the docking studies indicated that the interaction of ligands BVD10 and BVD15 with Y1 and Y4 receptors are different. These results were evaluated for selectivity of peptide analogues BVD10 and BVD15 towards the receptors.
Subject(s)
Models, Molecular , Neuropeptide Y/metabolism , Receptors, Neuropeptide Y/metabolism , Amino Acid Sequence , Humans , Ligands , Models, Chemical , Molecular Sequence Data , Protein Binding , Protein Conformation , Receptors, Neuropeptide Y/antagonists & inhibitors , Structure-Activity RelationshipABSTRACT
Abstract Neuropeptide Y (NPY), receptors belong to the G-protein coupled receptor superfamily. NPY mediates several physiological responses, such as blood pressure, food intake, sedation. These actions of NPY are mediated by six receptor subtypes denoted as Y(1)-Y(5) and y(6). Modeling of receptor subtypes and binding site identification is an important step in developing new therapeutic agents. We have attempted to model the three NPY receptor types, Y1, Y4, and Y5 using homology modeling and threading methods. The models are consistent with previously reported experimental evidence. To understand the interaction and selectivity of NPY analogues with different neuropeptide receptors, docking studies of two neuropeptide analogues (BVD10 and BVD15) with receptors Y1 and Y4 were carried out. Results of the docking studies indicated that the interaction of ligands BVD10 and BVD15 with Y1 and Y4 receptors are different. These results were evaluated for selectivity of peptide analogues BVD10 and BVD15 towards the receptors.