Mucolytic activity of bacterial and human chitinases.
Several pulmonary pathologies, like cystic fibrosis (CF), are characterized by hypersecretion and stasis of tenacious mucus. Bacterial glycosidases are known to degrade mucins but their use as mucolytic agents is questionable. The observation that bacterial chitinases degrade mucins and the recent discovery of human chitinases, which have been proposed to be involved in the genesis of asthma, prompted us to evaluate the mucolytic properties of human derived chitinases. The effect of these human chitinases, and bacterial chitinases (positive control), on the viscoelasticity of CF sputa and on the electrophoretic mobility of human mucins was tested. Commercial bacterial chitinase drastically degraded CF sputum, while human derived chitinases did not. Accordingly, the commercial bacterial chitinase was found to degrade mucins, whereas recombinant human chitinases did not. A thorough analysis of the commercial chitinase elucidated that contaminating proteases and also nucleases assisted in the mucolytic effect. Indeed, recombinant bacterial chitinases very slightly reduced the viscoelasticity of CF sputum, but they caused a significant degradation of the CF sputum when they were combined with proteases. In conclusion, this work shows that recombinant human and recombinant bacterial chitinases have no or very low mucolytic activities, respectively. The observed mucolytic properties of commercial bacterial chitinase are due to a synergistic effect between chitinolytic and proteolytic enzymes at one hand and at the other hand also due to the presence of contaminating nucleases.
Sanders
Niek N
NN
Laboratory of General Biochemistry and Physical Pharmacy, Faculty of Pharmacy, Ghent University, Harelbekestraat 72, 9000 Ghent, Belgium. Niek.Sanders@UGent.be
Eijsink
Vincent G H
VG
van den Pangaart
Petra S
PS
Joost van Neerven
R J
RJ
Simons
Peter J
PJ
De Smedt
Stefaan C
SC
Demeester
Joseph
J
D001419:Bacteria / Q000201:enzymology* / Q000378:metabolism*; D045744:Cell Line, Tumor; D002688:Chitinases / Q000235:genetics / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000201:enzymology; D003550:Cystic Fibrosis / Q000378:metabolism; D003851:Deoxyribonucleases / Q000378:metabolism; D004340:Drug Contamination; D004347:Drug Interactions; D004548:Elasticity; D005704:Gallbladder / Q000201:enzymology; D006801:Humans; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins / Q000235:genetics* / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D013183:Sputum / Q000201:enzymology / Q000378:metabolism; D014783:Viscosity
C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins; D011994:Recombinant Proteins; D003851:Deoxyribonucleases; D002688:Chitinases; D010447:Peptide Hydrolases