Purification and characterization of a papaya (Carica papaya L.) pectin methylesterase isolated from a commercial papain preparation

► A single PME was purified from the commercial papaya fruit latex preparation. ► Biochemical characterization showed it required metal ion salts for activation. ► The molecular weight average determined by MALDI-TOF MS was 35,135. ► A tryptic peptide ion mass fingerprint was generated for gene identification. ► CSPR assay indicated a processive enzyme action pattern.