PMID- 10336610
OWN - NLM
STAT- MEDLINE
DCOM- 19990624
LR  - 20190620
IS  - 0014-2956 (Print)
IS  - 0014-2956 (Linking)
VI  - 262
IP  - 2
DP  - 1999 Jun
TI  - Phospholipase C-delta3 binds with high specificity to phosphatidylinositol
      4,5-bisphosphate and phosphatidic acid in bilayer membranes.
PG  - 291-8
AB  - In order to acquire an understanding of phospholipase C-delta3 (PLC-delta3)
      action on substrate localized in lipid membrane we have studied the binding of
      human recombinant PLC-delta3 to large, unilamellar phospholipid vesicles (LUVs). 
      PLC-delta3 bound weakly to vesicles composed of phosphatidylcholine (PtdCho) or
      PtdCho plus phosphatidylethanolamine (PtdEtn) or phosphatidylinositol (PtdIns).
      The enzyme bound strongly to LUVs composed of PtdEtn + PtdCho and
      phosphatidylinositol 4,5-bisphosphate (PtdInsP2). The binding affinity (molar
      partition coefficient) of PLC-delta3 to PtdEtn + PtdCho + PtdInsP2 vesicles was
      7.7 x 105 m-1. High binding of PLC-delta3 was also observed for LUVs composed of 
      phosphatidic acid (PA). Binding of PLC-delta3 to phosphatidylserine (PtdSer)
      vesicles was less efficient. Calculated molar partition coefficient for binding
      of PLC-delta3 to PA and PtdSer vesicles was 1.6 x 104 m-1 and 9.4 x 102 m-1,
      respectively. Presence of PA in the LUVs containing PtdInsP2 considerably
      enhanced the binding of PLC-delta3 to the phospholipid membrane. Binding of
      PLC-delta3 to phospholipid vesicles was not dependent on Ca2+ presence. In the
      liposome assay PA caused a concentration-dependent increase in activity of
      PLC-delta3. The stimulatory effect of PA on PLC-delta3 was calcium-dependent. At 
      Ca2+ concentrations lower than 1 microm, no effect of PA on the activity of
      PLC-delta3 was observed. PA enhanced PLC-delta3 activity by increasing the Vmax
      and lowering Km for PtdInsP2. As the mol fraction of PA increased from 0-40 mol% 
      the enzyme Vmax increased 2.3-fold and Km decreased threefold. Based on the
      results presented, we assume that PA supports binding of PLC-delta3 to lipid
      membranes by interaction with the PH domain of the enzyme. The stimulatory effect
      of PA depends on calcium-dependent interaction with the C2 domain of PLC-delta3. 
      We propose that binding of PLC-delta3 to PA may serve as a mechanism for dynamic 
      membrane association and modulation of PLC-delta3 activity.
FAU - Pawelczyk, T
AU  - Pawelczyk T
AD  - Department of Molecular Medicine, Medical University of Gdansk, Poland.
      tkpaw@amedec.amg.gda.pl
FAU - Matecki, A
AU  - Matecki A
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Eur J Biochem
JT  - European journal of biochemistry
JID - 0107600
RN  - 0 (Isoenzymes)
RN  - 0 (Lipid Bilayers)
RN  - 0 (Phosphatidic Acids)
RN  - 0 (Phosphatidylinositol 4,5-Diphosphate)
RN  - 0 (Recombinant Proteins)
RN  - EC 3.1.4.- (Type C Phospholipases)
RN  - EC 3.1.4.11 (PLCD3 protein, human)
RN  - EC 3.1.4.11 (Phospholipase C delta)
SB  - IM
MH  - Humans
MH  - Isoenzymes/*metabolism
MH  - *Lipid Bilayers
MH  - Phosphatidic Acids/*metabolism
MH  - Phosphatidylinositol 4,5-Diphosphate/*metabolism
MH  - Phospholipase C delta
MH  - Recombinant Proteins/metabolism
MH  - Substrate Specificity
MH  - Type C Phospholipases/*metabolism
EDAT- 1999/05/21 00:00
MHDA- 1999/05/21 00:01
CRDT- 1999/05/21 00:00
PHST- 1999/05/21 00:00 [pubmed]
PHST- 1999/05/21 00:01 [medline]
PHST- 1999/05/21 00:00 [entrez]
AID - 10.1046/j.1432-1327.1999.00388.x [doi]
PST - ppublish
SO  - Eur J Biochem. 1999 Jun;262(2):291-8. doi: 10.1046/j.1432-1327.1999.00388.x.