Figure 1.

Predicted amino acid sequence of HD-5, based on the cDNA sequence.17 Single letter amino acid code for pre-pro-HD-5 is shown. Pro-HD-5 (with N terminus ESLQER and predicted mass of 8102 Da) was isolated from crypt cell extracts from normal and CD small intestine. In two CD crypt extracts, a smaller peptide [with N terminus ADEAT (arrow) and predicted mass of 7360 Da] was also isolated. In ileostomy fluid of controls, only the mature form of HD-5 (with N-terminal sequence ATCYCRT) was identified. In CD ileostomy fluid, the mature (with N-terminal sequence ATCYCRT and predicted mass of 3580 Da) and precursor forms of HD-5 were identified.