apoprotein Syllabification: (ap·o·pro·tein)Pronunciation: /ˌapəˈprōˌtēn, -ˈprōtēən/Definition of apoprotein noun Biochemistry a protein that together with a prosthetic group forms a particular biochemical molecule such as a hormone or enzyme. apoprotein in other Oxford dictionaries Definition of apoprotein in the British & World English dictionary