Computational screening of microalgae and cyanobacteria RuBisCO as potential precursor for bioactive peptides

Ribulose-1,5-bisphosphate carboxylase/oxygense (RuBisCO) is present in plants and autotrophic organisms like microalgae. The aim of this study was to perform an in silico evaluation of RuBisCo protein in microalgae and cyanobacteria as potential precursors of bioactive peptides, as well as to determine whether such peptides can be released by selected proteolytic enzymes. Fourteen RuBioCo sequences of microalgae and cyanobacteria were analysed by using the BIOPEP server amd database. The biological activity, enzyme action and calculation of active peptide tools were used to determine the frequency of occurrence of fragments, proteolysis, and the frequency of release of fragments with given activity by selected enzymes. The physio-chemical parameters of the selected sequences were performed with Protpram tool. Amongst the RuBisCo proteins of selected algae, Chaetoceros. calcitrans exhibits the best prospect as a source of DPP-IV inhibiting peptides, Chlorella pyrenoidosa for ACE inhibitor and Aphanizomenon flos-aquae for antioxidative, activating ubiquitin, and antiamnestic activities. High number of bioactive fragments in Aphanizomenon flos-aquae, Dunaliella salina, Chlorella pyrenoidosa, and Chlorella vulgaris are associated with a high content of glycine and proline amino acids that are most rich in biologically active fragments. Papain and Proteinase K, an enzyme with wide specificity, can release considerably more biologically active fragments than bromealin and chymotrpsin. These findings will contribute towards consumption of microalgal and cyanobacterial RuBisCO as alternative sources of bioactive peptide fragments based nutraceuticals for human.