LMPD Database

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LMP006342

UniProt Annotations

Entry Information
Gene Nameectonucleotide pyrophosphatase/phosphodiesterase 6
Protein EntryENPP6_HUMAN
UniProt IDQ6UWR7
SpeciesHuman
Comments
Comment typeDescription
Biophysicochemical PropertiesKinetic parameters: KM=344 uM for GPC ; KM=296 uM for 12:0-LPC ; KM=440 uM for 14:0-LPC ; KM=165 uM for 16:0-LPC ; KM=434 uM for 18:2-LPC ; KM=563 uM for 20:4-LPC ; Vmax=484 nmol/min/mg enzyme with GPC as substrate ; Vmax=463 nmol/min/mg enzyme with 12:0-LPC as substrate ; Vmax=367 nmol/min/mg enzyme with 14:0-LPC as substrate ; Vmax=89 nmol/min/mg enzyme with 16:0-LPC as substrate ; Vmax=285 nmol/min/mg enzyme with 18:2-LPC as substrate ; Vmax=470 nmol/min/mg enzyme with 20:4-LPC as substrate ; pH dependence: Optimum pH is 8.5-7.5. ;
Catalytic ActivityA lysophosphatidylcholine + H(2)O = a monoacylglycerol + phosphocholine.
Catalytic Activitysn-glycero-3-phosphocholine + H(2)O = glycerol + phosphocholine.
CofactorName=a divalent metal cation; Xref=ChEBI
Enzyme RegulationInhibited by EDTA and EGTA in vitro.
FunctionCholine-specific glycerophosphodiester phosphodiesterase. The preferred substrate may be lysosphingomyelin (By similarity). Hydrolyzes lysophosphatidylcholine (LPC) to form monoacylglycerol and phosphorylcholine but not lysophosphatidic acid, showing it has a lysophospholipase C activity. Has a preference for LPC with short (12:0 and 14:0) or polyunsaturated (18:2 and 20:4) fatty acids. Also hydrolyzes glycerophosphorylcholine and sphingosylphosphorylcholine efficiently. Hydrolyzes the classical substrate for phospholipase C, p-nitrophenyl phosphorylcholine in vitro, while it does not hydrolyze the classical nucleotide phosphodiesterase substrate, p-nitrophenyl thymidine 5'- monophosphate. Does not hydrolyze diacyl phospholipids such as phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine, phosphatidylglycerol and phosphatidic acid.
SimilarityBelongs to the nucleotide pyrophosphatase/phosphodiesterase family.
Subcellular LocationCell membrane ; Lipid-anchor, GPI-anchor . Note=A small amount of the protein may be found in the extracellular milieu.
SubunitHomodimer; disulfide-linked.
Tissue SpecificityPredominantly expressed in kidney and brain. In the kidney, expressed specifically in the proximal tubules and thin descending limbs of Henle (at protein level).