... vertebrates In conclusion, there is a single, large, evolutionarily conserved protrusion on the surface of the catalytic domain of PCSK9 The lack of other residue conservation on the PCSK9 surface ... of the mutants S15 3A -PCSK9, Q19 0A -PCSK9, R19 4A -PCSK9, D20 4A -PCSK9, K22 2A -PCSK9, R23 7A -PCSK9, D23 8A -PCSK9, D37 4A -PCSK9, C37 5A -PCSK9, S37 6A -PCSK9, T37 7A -PCSK9, C37 8A -PCSK9 and F37 9A -PCSK9 was determined ... using an antibody against the prodomain of PCSK9 The prodomains of R19 4A -PCSK9 and D20 4A -PCSK9 migrated normally (Fig 6) Thus, the two mutants were autocatalytically cleaved in a normal fashion...