Vol. 11, Issue 8 (2022)

Author(s):
Mathuranthagi TA, Kumar KK, Caroline Nirmala R, Varanavasiappan S and Muthuswamy A

Abstract:
Prolamin, the alcohol-soluble seed storage protein is the major seed protein in many cereals. Foxtail millet (Setaria italica) contains prolamin (Setarin) as major seed storage protein, which accounts > 50% of the total seed storage protein. To in-silico characterize the prolamin proteins of foxtail millet, sequence coding for 14.3 kDa, 20.4 kDa, 22 kDa, 22.4 kDa and 26 kDa prolamin of foxtail millet were retrieved from NCBI database. Protein physio-chemical characterization was done through Protparam and found that all the prolamin proteins were deficient in essential amino acids like cysteine, lysine, but contains relatively higher amount of essential amino acid, tryptophan. Isoelectric point of >7 indicated that all the proteins were basic in nature and low GRAVY value indicated that these proteins were hydrophobic in nature. Functional characterization by PRPSITE and Pfam revealed that all the proteins belong to the zein family of prolamins. Alpha helix was the dominant secondary structure found in all proteins. Multiple sequence alignment between foxtail millet prolamins show series of tandem repeats of glutamine (Q) residues. Phylogenetic analysis revealed that Setaria viridis were closely related with all the foxtail millet prolamins followed by other cereals. High level sequence homology was observed in signal peptide sequence of all the foxtail millet prolamins and signal peptide was prediction to cleave between 21 to 22 amino acids. The in-silico characterization of foxtail millet prolamins is able to assess the nutritional quality of prolamins, in addition to predicting the secondary structure and phylogenetic relationship with other cereal prolamins.