title: Maggot chymotrypsin I from Lucilia sericata is resistant to endogenous wound protease inhibitors.
abstract: BACKGROUND
  A chymotrypsin found in the secretions of Lucilia sericata and manufactured as a recombinant enzyme degrades chronic wound eschar ex vivo.
  
  
  OBJECTIVE
  To characterize the inhibition profile of the L. sericata recombinant chymotrypsin I.
  
  
  METHODS
  Activity of recombinant chymotrypsin I and its sensitivity to endogenous inhibitors were determined enzymatically using the fluorogenic substrate succinyl-alanyl-alanyl-prolyl-phenylalanyl-aminomethyl coumarin.
  
  
  RESULTS
  We report the presence of high concentrations of two endogenous inhibitors, α1-antichymotrypsin and α1-antitrypsin, in wound eschar and a trace of a third, α2-macroglobulin, with the potential to inhibit this debridement process. However, the addition of a soluble and inhibitor-containing extract of chronic wound eschar to chymotrypsin I did not affect activity of the enzyme, neither did the addition of purified native α1-antichymotrypsin or α1-antitrypsin, although chymotrypsin I was inhibited by α2-macroglobulin. Conversely, the mammalian equivalent, α-chymotrypsin, was inhibited by the purified native α1-antichymotrypsin, α1-antitrypsin and α2-macroglobulin and by the soluble extract of wound eschar.
  
  
  CONCLUSIONS
  The data suggest that the maggot-derived chymotrypsin I is biochemically distinct from human α-chymotrypsin and the lack of inhibition by wound eschar suggests a means by which chymotrypsin I activity survives within the wound to contribute towards debridement during maggot biotherapy.
authors.affiliation: Immune Modulation Research Group, School of Pharmacy, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: G
authors.initials: G
authors.lastname: Telford
authors.forename: A P
authors.initials: AP
authors.lastname: Brown
authors.forename: A
authors.initials: A
authors.lastname: Kind
authors.forename: J S C
authors.initials: JS
authors.lastname: English
authors.forename: D I
authors.initials: DI
authors.lastname: Pritchard
mesh_terms: D000818:Animals; D007611:Aprotinin / Q000494:pharmacology; D015153:Blotting, Western; D002918:Chymotrypsin / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004175:Diptera / Q000201:enzymology*; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods; D006801:Humans; D007814:Larva / Q000201:enzymology; D012867:Skin / Q000201:enzymology*; D014361:Trypsin Inhibitors / Q000494:pharmacology*; D014945:Wound Healing / Q000502:physiology; D014947:Wounds and Injuries / Q000201:enzymology* / Q000628:therapy
chemical_list: D014361:Trypsin Inhibitors; D007611:Aprotinin; D002918:Chymotrypsin