PMID- 18537075
OWN - NLM
STAT- MEDLINE
DCOM- 20080917
LR  - 20240109
IS  - 0032-0943 (Print)
IS  - 0032-0943 (Linking)
VI  - 74
IP  - 8
DP  - 2008 Jun
TI  - Elastase inhibition assay with peptide substrates - an example for the limited 
      comparability of in vitro results.
PG  - 852-8
LID - 10.1055/s-2008-1074549 [doi]
AB  - Many factors such as buffer, pH, or enzyme concentration influence the inhibitory 
      activity of test compounds in IN VITRO enzyme inhibition assays. The purpose of 
      this study was to evaluate whether the variation of the synthetic substrate has 
      an influence on the IC (50) values as well. As an exemplary enzyme, we have 
      chosen polymorphonuclear neutrophil elastase (PMNE), which is considered as a 
      promising target in the therapy for inflammatory and tumour diseases. A well 
      established, validated IN VITRO PMNE inhibition assay was performed with three 
      different synthetic peptide substrates (S-2484, L-1335, I-1270). As inhibitors 
      ursolic acid, unfractionated heparin (UFH), the semisynthetic glucan sulfate PS3, 
      and sulfated polysaccharides from the red algae DELESSERIA SANGUINEA (D.s.-SP), 
      were used. The maximum achievable PMNE inhibition by the test compounds was shown 
      to be determined by the substrate: 60 to 70 % (L-1335 and S-2484) or 90 % 
      (I-1270). Furthermore, the IC (50) values of the inhibitors turned out to 
      strongly vary in dependence on the substrate, although the used peptide 
      substrates are structurally very similar. The derived activities differed by up 
      to 480 %. In addition, the potencies of the test compounds in relation to each 
      other altered considerably. In conclusion, by the choice of the enzyme substrate, 
      both the apparent maximum activity and the IC (50) of an inhibitor can be 
      influenced. Therefore, only results from identical test systems should be 
      compared..
FAU - Groth, Inken
AU  - Groth I
AD  - Pharmaceutical Institute, University of Kiel, Kiel, Germany. 
      igroth@pharmazie.uni-kiel.de
FAU - Alban, Susanne
AU  - Alban S
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080606
PL  - Germany
TA  - Planta Med
JT  - Planta medica
JID - 0066751
RN  - 0 (Enzyme Inhibitors)
RN  - 0 (Peptides)
RN  - EC 3.4.21.37 (Leukocyte Elastase)
SB  - IM
MH  - Enzyme Inhibitors/*analysis
MH  - Humans
MH  - Inhibitory Concentration 50
MH  - Leukocyte Elastase/*antagonists & inhibitors
MH  - Peptides/*metabolism
MH  - Reference Standards
MH  - Substrate Specificity
EDAT- 2008/06/10 09:00
MHDA- 2008/09/18 09:00
CRDT- 2008/06/10 09:00
PHST- 2008/06/10 09:00 [pubmed]
PHST- 2008/09/18 09:00 [medline]
PHST- 2008/06/10 09:00 [entrez]
AID - 10.1055/s-2008-1074549 [doi]
PST - ppublish
SO  - Planta Med. 2008 Jun;74(8):852-8. doi: 10.1055/s-2008-1074549. Epub 2008 Jun 6.