Updated project metadata. Here we describe the post translational modifications on vaccine candidate proteins from Cryptosporidium parvum. We have identified O-glycosylated peptides from GP15, GP40, GP900, and a novel mucin-like protein referred to as GP20. In addition, we have discovered that the immune dominant antigen, CP23, contains both N-myristoyl and C-palmitoyl modifications on the N-terminal region of the protein.