Kinetics of Phycocyanobilin Cleavage from C-Phycocyanin by Methanolysis

Phycocyanobilin (PCB) is an important linear tetrapyrrolic molecule for food as well as pharmaceutical industry. It is obtained from blue-green algae, where it is attached covalently to phycobiliproteins (C-PC and APC) present in the light harvesting complexes. In this work, cleavage of PCB from phycobiliproteins present in the extract of Arthrospira platensis by methanolysis is investigated. Different initial concentrations (25 mg/mL, 10 mg/mL, and 5 mg/mL) of proteins are used in order to investigate the effect of protein aggregation on process yield. A kinetic model is developed by fitting the experimental data for methanolysis. Results show that the kinetics follows a pseudo first order kinetics and remains unaffected due to the different initial concentration of phycobiliproteins. Moreover, yield of PCB in the cleavage process is found to be proportional to the initial concentration of phycobiliproteins.