The design and enzymatic hydrolysis of activatable cell-penetrating peptide

The paper is aimed to study the enzymatic hydrolysis of the activatable cell-penetrating peptide (ACPP) that was designed and synthesized.  The ACPP was composed of three parts, polyanionic sequence  peptide, peptide sequence that specifically cleaved by matrix metalloproteinase (MMP) and cell penetrating  peptide (CPP).  The ACPP was hydrolyzed by type IV collagenase (MMP-2/9) under the condition of 37 ℃  and was monitored by reversed-phase high performance liquid chromatography (RP-HPLC).  The efflux of  peak was collected and detected by matrix assisted laser desorption ionization orthogonal time of flight mass spectrometry (MALDIO-TOF-MS) to speculate the sequences of the peptide fragments.  The results indicated that the ACPP could be cleaved by type IV collagenase at target site as predicted, released CPP.  The half life  of the cleavage was about 4 h.  Meanwhile, the peptide fragments may be cleaved again at other sites by type  IV collagenase.