Proteins are a class of biomolecules composed of amino acid chains.

Biochemistry

• Antifreeze protein, class of polypeptides produced by certain fish, vertebrates, plants, fungi and bacteria
• Conjugated protein, protein that functions in interaction with other chemical groups attached by covalent bonds
• Denatured protein, protein which has lost its functional conformation
• Matrix protein, structural protein linking the viral envelope with the virus core
• Protein A, bacterial surface protein that binds antibodies
• Protein A/G, recombinant protein that binds antibodies
• Protein C, anticoagulant
• Protein G, bacterial surface protein that binds antibodies
• Protein L, bacterial surface protein that binds antibodies
• Protein S, plasma glycoprotein
• Protein Z, glycoprotein
• Protein catabolism, the breakdown of proteins into amino acids and simple derivative compounds
• Protein complex, group of two or more associated proteins
• Protein electrophoresis, method of analysing a mixture of proteins by means of gel electrophoresis
• Protein folding, process by which a protein assumes its characteristic functional shape or tertiary structure
• Protein isoform, version of a protein with some small differences
• Protein kinase, enzyme that modifies other proteins by chemically adding phosphate groups to them
• Protein ligands, atoms, molecules, and ions which can bind to specific sites on proteins
• Protein microarray, piece of glass on which different molecules of protein have been affixed at separate locations in an ordered manner
• Protein phosphatase, enzyme that removes phosphate groups that have been attached to amino acid residues of proteins
• Protein purification, series of processes intended to isolate a single type of protein from a complex mixture
• Protein sequencing, protein method
• Protein splicing, intramolecular reaction of a particular protein in which an internal protein segment is removed from a precursor protein
• Protein structure, unique three-dimensional shape of amino acid chains
• Protein targeting, mechanism by which a cell transports proteins to the appropriate positions in the cell or outside of it
• Protein-protein docking, the determination of the molecular structure of complexes formed by two or more proteins
• Protein-protein interaction, the association of protein molecules and the study of these associations from the perspective of biochemistry
• RACK protein, receptor responsible for the binding of active forms of the protein kinase C family of enzymes
• Secretory protein, protein which is secreted by a cell

Bioengineering

• Protein production, the generation of a pure protein
• Protein design, the design of new protein molecules from scratch
• Protein engineering, application of science, mathematics, and economics to the process of developing useful or valuable proteins

Genetics

• Fibrous protein, long filamentous protein molecule that forms one of the two main classes of tertiary structure protein
• Fusion protein, protein created through genetic engineering from two or more proteins
• Globular protein, one of the two main protein classes
• Protein family, group of evolutionarily related proteins
• Protein methods, techniques used to study proteins
• Protein subunit, single protein molecule that assembles with other protein molecules to form a multimeric or oligomeric protein
• Regulatory protein, term used in genetics to describe a protein involved in regulating gene expression

Medicine

• Tau protein, microtubule-associated protein found in neurons in the brain

Membrane biology

• G protein, family of proteins involved in second messenger cascades
• Membrane protein, protein molecule that is attached to, or associated with, the membrane of a cell or an organelle
• Transmembrane protein, integral membrane protein that spans from the internal to the external surface of the biological membrane
• Transport protein, protein involved in the movement of a chemical across a biological membrane

Nutrition

• Carbohydrates (nutrient), role of protein in nutrition
• Casein, a family of related phosphoproteins that are commonly found in mammalian milk, comprising about 80% of the proteins in cow's milk.
• Mycoprotein, fungal protein sometimes used as a meat substitute.
• Protein supplement, dietary supplement or a bodybuilding supplement, and may take the form of a protein bar or protein powder.
• Pea protein, derived and extracted from yellow and green split peas, Pisum sativum.
• Rice protein, an alternative to the more common whey and soy protein isolates.
• Soy protein, storage protein held in discrete particles called protein bodies
• Whey protein, the name for a collection of globular proteins that can be isolated from whey