INTRODUCTION
Hydrocarbon stapled peptides have important potential in the development of peptide drugs. Peptides have high potency, high specificity and few side effects, but are rapidly degraded by protease enzymes.  The hydrocarbon cross links of stapled peptides constrain the peptide in an a-helix conformation, favoring binding for peptides that bind to their receptor in an a-helix conformation.  Additionally, in a helical structure, the polar amide backbone is less exposed producing greater resistance to protease enzymes and increased penetration of cell membranes.   Double stapling of an HIV-1 fusion inhibitor greatly improved its pharmacokinetic properties, including oral availability. (1)

STAPLED PEPTIDES AS POTENTIAL DRUG LEADS
Gregory L. Verdine and coworkers reported the first hydrocarbon stapled peptides and their protease resistance. (2) Soon after, stapled peptides that inhibited the growth of human leukemia xenografts were reported. (3) These stapled peptides are potential leads to new cancer treatments.
Stapled peptides provide new antiviral drug leads.  Stapled peptides targeting HIV- ...