The larval form of the parasite Schistosoma mansoni infects humans by penetrating the skin. The larva secretes enzymes that catalyze the cleavage of peptide bonds between residues X and Y in the sequence -Gly-Pro-X-Y- where X and Y can be any of several amino acids. Why is this enzyme important for the parasite? Relate your answer to the statement about collagen which is the sequence of the protein in the helical region consists of multiple repeats of the form -Gly-X-Y- where X is often Pro and Y is often a modified Pro called 4-hydroxyproline