( ( ( Sanger 's ) ( principal conclusion ) ) ( ( was ( that ( ( ( the ( two ( polypeptide chains ) ) ) ( of ( the ( protein insulin ) ) ) ) ( had ( ( ( ( precise ( amino ( acid sequences ) ) ) and ) ( , ( ( by extension ) , ) ) ) ( that ( ( every protein ) ( had ( a ( unique sequence ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Sanger) (POS 's)) (JJ principal) (NN conclusion)) (VP (VBD was) (SBAR (IN that) (S (NP (NP (DT the) (CD two) (JJ polypeptide) (NNS chains)) (PP (IN of) (NP (DT the) (NN protein) (NN insulin)))) (VP (VBD had) (NP (NP (JJ precise) (JJ amino) (JJ acid) (NNS sequences)) (CC and) (PRN (, ,) (PP (IN by) (NP (NN extension))) (, ,)) (SBAR (IN that) (S (NP (DT every) (NN protein)) (VP (VBD had) (NP (DT a) (JJ unique) (NN sequence)))))))))) (. .)))
Sanger's principal conclusion was that the two polypeptide chains of the protein insulin had precise amino acid sequences and, by extension, that every protein had a unique sequence.
(ROOT (S (NP (NNP Insulin)) (VP (VBZ is) (VP (VBN made) (PRT (RP up)) (PP (IN of) (NP (CD two) (JJ polypeptide) (NNS chains))))) (. .)))