title: Purification and characterization of mycobacterial phospholipase A: an activity associated with mycobacterial cutinase.
abstract: We describe mycobacterial phospholipase A activity (MPLA) and, using reverse genetics, have associated this activity with putative mycobacterial cutinase. PLAs, which hydrolyze fatty acids on phospholipids, play a significant role in human inflammatory states and disease pathogenesis. In prokaryotes, the recognition of their role in virulence is more recent. Cutinases are serine esterases whose primary substrate is cutin, the waxy exterior layer of plants. Mycobacterium tuberculosis has maintained seven putative cutinases, though it should not encounter cutin; we demonstrate that known cutinases and MPLA cleave phospholipids in a PLA-type manner and also hydrolyze Tween. We analyzed cutinase motifs in mycobacteria and found the motif very prevalent. All mycobacteria tested had MPLA activity. These studies suggest an alternative use for putative cutinases by the M. tuberculosis group that is likely related to MPLA activity and lipid metabolism.
authors.affiliation: Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, CO 80045, USA. sarah.parker@uchsc.edu
authors.forename: Sarah K
authors.initials: SK
authors.lastname: Parker
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Curtin
authors.forename: Michael L
authors.initials: ML
authors.lastname: Vasil
mesh_terms: D000595:Amino Acid Sequence; D002265:Carboxylic Ester Hydrolases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D006868:Hydrolysis; D007700:Kinetics; D008563:Membrane Lipids / Q000378:metabolism; D008969:Molecular Sequence Data; D009161:Mycobacterium / Q000201:enzymology* / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000201:enzymology / Q000235:genetics; D009578:Nitrobenzenes / Q000378:metabolism; D010741:Phospholipases A / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011136:Polysorbates / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D008563:Membrane Lipids; D009578:Nitrobenzenes; D011136:Polysorbates; C110057:4-nitrophenethyl bromide; C000521:cutin; D002265:Carboxylic Ester Hydrolases; C019952:cutinase; D010741:Phospholipases A