The presently disclosed subject matter discloses isolated ADAM 10 modulating peptides and related compounds useful for studying the biological functions of ADAM 10 and for the treatment of diseases such as cancer, neurological disorders, asthma, and allergic responses, and disorders characterized at least in part by the presence of one or more of inflammation, excess cell proliferation, angiogenesis, and excess soluble CD23. In one aspect, the presently disclosed subject matter provides isolated mouse and human ADAM 10 prodomain comprising the sequence set forth in SEQ ID NOs 1-8, or a sequence having at least 95% homology to any of SEQ ID NOs 1-8 and having the functionality of modulating ADAM 10 activity.