Antibody
Human
Antigens are peptides or recombinant or native dependent on the production method.Fusion proteins or chimeric proteins are proteins created through the joining of two or more genes that originally coded for separate proteins. A GFP gene is often used as tag to a reporter gene. Fusion lentiverctors can be used as viral particles to produce proteins that carry for example a GFP tag. Antigen purification of recombinant fusion tag proteins is a frequent strategy using a Fralg tag.The receptors are ligand binding factors of type 1, 2 or 3 and protein-molecules that receive chemical-signals from outside a cell. When such chemical-signals couple or bind to a receptor, they cause some form of cellular/tissue-response, e.g. a change in the electrical-activity of a cell. In this sense, am olfactory receptor is a protein-molecule that recognizes and responds to endogenous-chemical signals, chemokinesor cytokines e.g. an acetylcholine-receptor recognizes and responds to its endogenous-ligand, acetylcholine. However, sometimes in pharmacology, the term is also used to include other proteins that are drug-targets, such as enzymes, transporters and ion-channels.