passages.id: split_8_test_2172_passage
passages.type: progene_text
passages.text: Pro - CPA5 was not enzymatically active toward standard CPA substrates , but after incubation with prohormone convertase 4 the resulting protein was able to cleave furylacryloyl - Gly - Leu , with 3-4 - fold greater activity at pH 7.4 than at 5.6 .