The Secondary Structure of Phospholamban: A Two-Dimensional NMR Study

• Published in: Biochemical and biophysical research communications Vol. 217; no. 3; pp. 1200 - 1207
• Main Authors: Maslennikov, I.V., Sobol, A.G., Anagli, J., James, P., Vorherr, T., Arseniev, A.S., Carafoli, E.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 26-12-1995
• Subjects: Amino Acid Sequence; Calcium-Binding Proteins - chemistry; Magnetic Resonance Spectroscopy; Membrane Proteins - chemistry; Molecular Sequence Data; Muscle Proteins - chemistry; Phosphoproteins - chemistry; Protein Structure, Secondary
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1006/bbrc.1995.2896

Phospholamban (PLN) is an intrinsic membrane protein of 52 amino acids which regulates the Ca2+ pump of the sarcoplasmic reticulum of heart, slow-twitch and smooth muscle (SR): it is normally assumed to exist in the membrane as a homopentamer. A monomeric analogue of phospholamban PLN(C41F), in which Cys41 was replaced by a Phe,was synthesized and its conformation studied by 1H NMR spectroscopy in a 1:1 mixture of chloroform/methanol. Most of the resonances in the 1H NMR spectra were assigned. The work has shown that the C-terminal hydrophobic portion forms a very stable α-helix. The hydrophilic N-terminal part adopts an α-helix configuration which is much less stable except for the stretch containing the phosphorylation sites.