Efficient debridement of the wound bed following the removal of microbial load prevents its progression into a chronic wound. Bacterial infection and excessive proteolysis characterize impaired healing and therefore, their inhibition might restore the disturbed equilibrium in the healing process. Human placental extract exhibits reversible, non‐competitive inhibition towards Proteinase K, a microbial protease, by stabilizing it against auto‐digestion. Scattering and fluorescence studies followed by biochemical analysis indicated the involvement of a glycan moiety. Surface plasmon resonance demonstrated specific interaction of heparin with Proteinase K having Kd in μM range. Further, Proteinase K contains sequence motifs similar to other heparin‐binding proteins. Molecular docking revealed presence of clefts suitable for binding of heparin‐derived oligosaccharides. Comprehensive analysis of this inhibitory property of placental extract partly explains its efficacy in curing wounds with common bacterial infections. J. Cell. Physiol. 229: 1212–1223, 2014. © 2014 Wiley Periodicals, Inc.