(informal, biochemistry) Any protein that normally exists combined with another entity (metal, carbohydrate or lipid etc), free from its normal attachment.

(biochemistry) Any of a family of small proteins that attach themselves to other proteins within cells and modify their function

(countable or uncountable) A protein found in leaves extracted for use as a food for humans.

(biochemistry) Any of a class of proteins that are able to move on a suitable substrate, being powered by the hydrolysis of ATP, and are involved in the conversion of chemical energy into mechanical work.

(biochemistry) Any of many proteins, found especially in seeds, that act as reservoirs of amino acids and metal ions that are needed by growing organisms

(biochemistry, genetics) Any protein produced via a mutated gene

(neurology) A protein abundant especially in the neurons of the human central nervous system that stabilizes microtubules, and when misfolded is associated with forms of dementia such as Alzheimer's and Parkinson's diseases.

(biochemistry) A protein that is associated with a biological membrane; association typically refers to either the ability to copurify membrane lipids with said protein or the ability to visualize a physical association in situ.

(molecular biology) a biological research reagent which binds to a specific target protein

plural of protein binder