( ( This receptor ) ( ( contains ( ( four ( polypeptide chains ) ) ( -LRB- ( ( ( ( ( ( alpha , ) beta ) , ) and ) ( two gammas ) ) -RRB- ) ) ) ) . ) )
(ROOT (S (NP (DT This) (NN receptor)) (VP (VBZ contains) (NP (NP (CD four) (JJ polypeptide) (NNS chains)) (PRN (-LRB- -LRB-) (NP (NP (NNP alpha)) (, ,) (NP (NN beta)) (, ,) (CC and) (NP (CD two) (NNS gammas))) (-RRB- -RRB-)))) (. .)))
This receptor contains four polypeptide chains ( alpha , beta , and two gammas).
(ROOT (S (NP (NNP Insulin)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (CD two) (JJ polypeptide) (NNS chains))))) (. .)))