Fig. 5: PG binding and degradation by pseudoalterin.

a SDS-PAGE analysis of the binding ability of pseudoalterin on three insoluble polysaccharides and PG. The experiments were performed with a fixed amount of pseudoalterin (0.2 mg ml⁻¹) and increasing concentrations of substrates. “S” and “P” refer to the amount of protein present in the supernatant and the pellet after centrifugation, respectively. BSA in place of pseudoalterin was used as a negative control. Each graph is a representative of at least three repeats. b Chiral derivatization-HPLC analysis of the d/l-amino acids and the peptides released from PG of strain MCCC0423 by pseudoalterin hydrolysis. 5aa is a mixture of five standard amino acids (Gly, d/l-Ala, d-Glu and l-Lys). c Analysis of the amino acids released from PG of strain MCCC0423 by pseudoalterin hydrolysis with an Automatic Amino Acid Analyzer (Hitachi L8900, Japan). Data are from triplicate experiments (mean ± SD). d The cleavage sites of pseudoalterin on strain MCCC0423 PG. Arrows indicate the cleavage sites determined according to analysis of the products released by pseudoalterin from two synthetic PG peptides, AaKAGGGGGA and Lactic acid-AeKAGG. Red and black arrows indicate the preferred and less preferred bonds by pseudoalterin, respectively, which are deduced based on the relative production of the released products in MS spectra (Supplementary Figs. 4 and 5). M, NAM; G, NAG. Source data are provided as a Source Data file.