( It ( ( consists ( of ( ( ( four ( polypeptide chains ) ) , ) ( ( two each ) ( of ( ( alpha and ) beta ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ consists) (PP (IN of) (NP (NP (CD four) (JJ polypeptide) (NNS chains)) (, ,) (NP (NP (NP (CD two)) (NP (DT each))) (PP (IN of) (NP (NN alpha) (CC and) (NN beta))))))) (. .)))
It consists of four polypeptide chains, two each of alpha and beta.
(ROOT (S (NP (NNP Insulin)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (CD two) (JJ polypeptide) (NNS chains))))) (. .)))