Natural chlorophyll metabolites have exhibited physiological activity in vitro. In this study, a recombinant chlorophyllase1 gene from Chlamydomonas reinhardtii (CrCLH1) was isolated and characterized. Recombinant CrCLH1 can perform chlorophyll dephytylation and produce chlorophyllide and phytol. In a transient assay, the subcellular localization of CrCLH1-green fluorescent protein was determined to be outside the chloroplast. Biochemical analyses of the activity of recombinant CrCLH1 indicated that its optimal pH value and temperature are 6.0 and 40 °C, respectively. Enzyme kinetic data revealed that the recombinant CrCLH1 had a higher catalytic efficiency for chlorophyll a than for chlorophyll b and bacteriochlorophyll a. According to high-performance liquid chromatography analysis of chlorophyll hydrolysis, recombinant CrCLH1 catalyzed the conversion of chlorophyll a to pheophorbide a at pH 5. Therefore, recombinant CrCLH1 can be used as a biocatalyst to produce chlorophyllide derivatives.
Keywords: Chlamydomonas reinhardtii; chlorophyllase; chlorophyllide derivatives; enzyme kinetics.