Amazing stability of the arginine-phosphate electrostatic interaction.
Electrostatic interactions between a basic epitope containing adjacent arginine residues and an acidic epitope containing a phosphorylated serine are involved in receptor heteromerization. In the present study, we demonstrate that this arginine-phosphate electrostatic interaction possesses a "covalent-like" stability. Hence, these bonds can withstand fragmentation by mass spectrometric collision-induced dissociation at energies similar to those that fragment covalent bonds and they demonstrate an extremely low dissociation constant by plasmon resonance. The present work also highlights the importance of phosphorylation-dephosphorylation events in the modulation of this electrostatic attraction. Phosphorylation of the acidic epitope, a casein kinase one consensus site, makes it available to interact with the basic epitope. On the other hand, phosphorylation of serine and/or threonine residues adjacent to the basic epitope, a protein kinase A consensus site, slows down the attraction between the epitopes. Although analyzed here in the frame of receptor heteromerization, the arginine-phosphate electrostatic interaction most likely represents a general mechanism in protein-protein interactions.
Woods
Amina S
AS
National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health/DHHS, 5000 Nathan Shock Drive, Baltimore, MD 21224, USA. awoods@intra.nida.nih.gov
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D000595:Amino Acid Sequence; D001120:Arginine / Q000737:chemistry*; D000939:Epitopes; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis / Q000235:genetics; D010710:Phosphates / Q000737:chemistry*; D010766:Phosphorylation; D018048:Receptors, Purinergic P2 / Q000737:chemistry; D015398:Signal Transduction; D055672:Static Electricity; D020349:Surface Plasmon Resonance
D000939:Epitopes; D010455:Peptides; D010710:Phosphates; D018048:Receptors, Purinergic P2; D001120:Arginine