u2212 1 less than about 10 u2212 4 sec u2212 1 and also less than about 10 u2212 5 sec u2212 1 the binding peptides of the invention will not bind with any significance to the anti target while not meant to limit the invention a preferred binding ligand may have a k d for the anti target greater than about 10 u2212 4 m and preferably greater than about 10 u2212 1 m the binding peptides according to the invention may be characterized not only by the binding affinity of the ligand to a target but also may be characterized by the selectivity of the ligand target complex the selectivity of ligand binding for a target compared to ligand binding to an anti target can be defined by a ratio of k d ec 50 or ic 50 in the range of about 1 5 1 to 500 1 in one aspect selectivity is at least about 2 1 at least about 3 1 at least about 5 1 at least about 10 1 at least about 20 1 at least about 30 1 at least about 50 1 and at least about 100 1 methods for measuring binding affinities and selectivity are well known in the art and these methods include but are not limited to measurement by radio labeled release and competition assay by isothermal titration calorimetry biosensor binding assays morton amp myszka 1998 methods enzymol 295 268 294 by fluorescence and chemiluminescence spectroscopy and by mass spectrophotometry geo et al 1996 j med chem 39 1949 in one embodiment preferred skin binding peptides according to the invention are listed in table 1 particularly preferred embodiments include skin binding peptides having an amino acid sequence of seq id.