PMID- 21615172
OWN - NLM
STAT- MEDLINE
DCOM- 20111101
LR  - 20211020
IS  - 1520-5126 (Electronic)
IS  - 0002-7863 (Print)
IS  - 0002-7863 (Linking)
VI  - 133
IP  - 27
DP  - 2011 Jul 13
TI  - Pb2+ as modulator of protein-membrane interactions.
PG  - 10599-611
LID - 10.1021/ja2032772 [doi]
AB  - Lead is a potent environmental toxin that mimics the effects of divalent metal 
      ions, such as zinc and calcium, in the context of specific molecular targets and 
      signaling processes. The molecular mechanism of lead toxicity remains poorly 
      understood. The objective of this work was to characterize the effect of Pb(2+) 
      on the structure and membrane-binding properties of C2alpha. C2alpha is a peripheral 
      membrane-binding domain of Protein Kinase Calpha (PKCalpha), which is a well-documented 
      molecular target of lead. Using NMR and isothermal titration calorimetry (ITC) 
      techniques, we established that C2alpha binds Pb(2+) with higher affinity than its 
      natural cofactor, Ca(2+). To gain insight into the coordination geometry of 
      protein-bound Pb(2+), we determined the crystal structures of apo and 
      Pb(2+)-bound C2alpha at 1.9 and 1.5 A resolution, respectively. A comparison of these 
      structures revealed that the metal-binding site is not preorganized and that 
      rotation of the oxygen-donating side chains is required for the metal 
      coordination to occur. Remarkably, we found that holodirected and hemidirected 
      coordination geometries for the two Pb(2+) ions coexist within a single protein 
      molecule. Using protein-to-membrane Forster resonance energy transfer (FRET) 
      spectroscopy, we demonstrated that Pb(2+) displaces Ca(2+) from C2alpha in the 
      presence of lipid membranes through the high-affinity interaction with the 
      membrane-unbound C2alpha. In addition, Pb(2+) associates with 
      phosphatidylserine-containing membranes and thereby competes with C2alpha for the 
      membrane-binding sites. This process can contribute to the inhibitory effect of 
      Pb(2+) on the PKCalpha activity.
FAU - Morales, Krystal A
AU  - Morales KA
AD  - Department of Biochemistry and Biophysics, Texas A&M University, College Station, 
      Texas 77843, USA.
FAU - Lasagna, Mauricio
AU  - Lasagna M
FAU - Gribenko, Alexey V
AU  - Gribenko AV
FAU - Yoon, Youngdae
AU  - Yoon Y
FAU - Reinhart, Gregory D
AU  - Reinhart GD
FAU - Lee, James C
AU  - Lee JC
FAU - Cho, Wonhwa
AU  - Cho W
FAU - Li, Pingwei
AU  - Li P
FAU - Igumenova, Tatyana I
AU  - Igumenova TI
LA  - eng
GR  - R01 GM068849/GM/NIGMS NIH HHS/United States
GR  - T32 GM008523/GM/NIGMS NIH HHS/United States
GR  - GM68849/GM/NIGMS NIH HHS/United States
GR  - R01 GM052598/GM/NIGMS NIH HHS/United States
GR  - 2-T32GM008523-13/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20110617
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
RN  - 0 (Environmental Pollutants)
RN  - 2P299V784P (Lead)
RN  - EC 2.7.11.13 (Protein Kinase C-alpha)
RN  - SY7Q814VUP (Calcium)
SB  - IM
MH  - Binding Sites
MH  - Calcium/chemistry
MH  - Cell Membrane/*chemistry
MH  - Environmental Pollutants/*toxicity
MH  - Fluorescence Resonance Energy Transfer
MH  - Lead/*toxicity
MH  - Protein Binding
MH  - Protein Conformation
MH  - Protein Kinase C-alpha/*antagonists & inhibitors/*chemistry
PMC - PMC3646060
MID - NIHMS305680
EDAT- 2011/05/28 06:00
MHDA- 2011/11/02 06:00
PMCR- 2013/05/06
CRDT- 2011/05/28 06:00
PHST- 2011/05/28 06:00 [entrez]
PHST- 2011/05/28 06:00 [pubmed]
PHST- 2011/11/02 06:00 [medline]
PHST- 2013/05/06 00:00 [pmc-release]
AID - 10.1021/ja2032772 [doi]
PST - ppublish
SO  - J Am Chem Soc. 2011 Jul 13;133(27):10599-611. doi: 10.1021/ja2032772. Epub 2011 
      Jun 17.