(15)N Solid-state NMR spectroscopic studies on phospholamban at its phosphorylated form at ser-16 in aligned phospholipid bilayers

Biochim Biophys Acta. 2010 Mar;1798(3):312-7. doi: 10.1016/j.bbamem.2009.12.020. Epub 2010 Jan 4.

Abstract

Wild-type phospholamban (WT-PLB) is a pentameric transmembrane protein that regulates the cardiac cycle (contraction and relaxation). From a physiological prospective, unphosphorylated WT-PLB inhibits sarcoplasmic reticulum ATPase activity; whereas, its phosphorylated form relieves the inhibition in a mechanism that is not completely understood. In this study, site-specifically (15)N-Ala-11- and (15)N-Leu-7-labeled WT-PLB and the corresponding phosphorylated forms (P-PLB) were incorporated into 1,2-dioleoyl-sn-glycero-3-phosphocholine/2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPC/DOPE) mechanically oriented lipid bilayers. The aligned (15)N-labeled Ala-11 and Leu-7 WT-PLB samples show (15)N resonance peaks at approximately 71ppm and 75ppm, respectively, while the corresponding phosphorylated forms P-PLB show (15)N peaks at 92ppm and 99ppm, respectively. These (15)N chemical shift changes upon phosphorylation are significant and in agreement with previous reports, which indicate that phosphorylation of WT-PLB at Ser-16 alters the structural properties of the cytoplasmic domain with respect to the lipid bilayers.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Calcium-Binding Proteins / chemistry*
  • Calcium-Binding Proteins / metabolism*
  • Electrophoresis, Polyacrylamide Gel
  • Lipid Bilayers / metabolism*
  • Magnetic Resonance Spectroscopy
  • Nitrogen Isotopes
  • Phosphatidylcholines / metabolism*
  • Phosphatidylethanolamines / metabolism*
  • Phosphorylation
  • Phosphoserine / metabolism*

Substances

  • 1,2-dioleoyl-glycero-3-phosphatidyl ethanolamine
  • Calcium-Binding Proteins
  • Lipid Bilayers
  • Nitrogen Isotopes
  • Phosphatidylcholines
  • Phosphatidylethanolamines
  • phospholamban
  • Phosphoserine
  • 1,2-oleoylphosphatidylcholine