The present invention relates generally to small peptide-based constructs, including derivatized constructs, and their therapeutic uses. The constructs and derivatized constructs can have at least one of heparin binding, heparin neutralizing, endothelial cell proliferation inhibiting, antiangiogenic, LPS binding, LPS neutralization, or antimicrobial properties. The sequences of these constructs are based on a reverse subsequence derived from Domain II of bactericidal/permeability-increasing protein (BPI).