ACE vs proteinase

ACE and proteinase both are nouns.

Word	Noun	Adjective	Verb	Adverb
ACE	Yes	No	No	No
proteinase	Yes	No	No	No

As nouns, proteinase is a hypernym of ACE; that is, proteinase is a word with a broader meaning than ACE:

ACE: proteolytic enzyme that converts angiotensin I into angiotensin II
proteinase: any enzyme that catalyzes the splitting of proteins into smaller peptide fractions and amino acids by a process known as proteolysis

Other hypernyms of ACE include peptidase, protease, proteolytic enzyme.

ACE (noun)	proteinase (noun)
a major strategic headquarters of NATO; safeguards an area extending from Norway to Turkey	any enzyme that catalyzes the splitting of proteins into smaller peptide fractions and amino acids by a process known as proteolysis
proteolytic enzyme that converts angiotensin I into angiotensin II