title: Multiple phospholipid substrates of phospholipase C/sphingomyelinase HR2 from Pseudomonas aeruginosa.
abstract: The activity of phospholipase C/sphingomyelinase HR(2) (PlcHR(2)) from Pseudomonas aeruginosa was characterized on a variety of substrates. The enzyme was assayed on liposomes (large unilamellar vesicles) composed of PC:SM:Ch:X (1:1:1:1; mol ratio) where X could be PE, PS, PG, or CL. Activity was measured directly as disappearance of substrate after TLC lipid separation. Previous studies had suggested that PlcHR(2) was active only on PC or SM. However we found that, of the various phospholipids tested, only PS was not a substrate for PlcHR(2). All others were degraded, in an order of preference PC>SM>CL>PE>PG. PlcHR(2) activity was sensitive to the overall lipid composition of the bilayer, including non-substrate lipids.
authors.affiliation: Unidad de Biofísica (Centro Mixto CSIC-UPV/EHU), Departamento de Bioquímica, Universidad del País Vasco, Barrio Sarriena s/n, 48940 Leioa, Bilbao, Spain.
authors.forename: David J
authors.initials: DJ
authors.lastname: López
authors.forename: M Isabel
authors.initials: MI
authors.lastname: Collado
authors.forename: Maitane
authors.initials: M
authors.lastname: Ibarguren
authors.forename: Adriana I
authors.initials: AI
authors.lastname: Vasil
authors.forename: Michael L
authors.initials: ML
authors.lastname: Vasil
authors.forename: Félix M
authors.initials: FM
authors.lastname: Goñi
authors.forename: Alicia
authors.initials: A
authors.lastname: Alonso
mesh_terms: D008081:Liposomes / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D013108:Sphingomyelin Phosphodiesterase / Q000378:metabolism*; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000378:metabolism*
chemical_list: D008081:Liposomes; D010743:Phospholipids; D010738:Type C Phospholipases; D013108:Sphingomyelin Phosphodiesterase