New insights into P2X7 receptor regulation: Ca2+-calmodulin and GDP bind to the soluble P2X7 ballast domain.

Sander S, Müller I, Alai MG, Nicke A, Tidow H, J Biol Chem :102495 (2022) Europe PMC

SASDPF4 – P2X7 ballast domain in complex with Ca2+-calmodulin

Calmodulin-1
P2X purinoceptor 7
MWexperimental 51 kDa
MWexpected 41 kDa
VPorod 73 nm3
log I(s) 8.50×103 8.50×102 8.50×101 8.50×100
Calmodulin-1 P2X purinoceptor 7 small angle scattering data  s, nm-1
ln I(s)
Calmodulin-1 P2X purinoceptor 7 Guinier plot ln 8.50×103 Rg: 3.2 nm 0 (3.2 nm)-2 s2
(sRg)2I(s)/I(0)
Calmodulin-1 P2X purinoceptor 7 Kratky plot 1.104 0 3 sRg
p(r)
Calmodulin-1 P2X purinoceptor 7 pair distance distribution function Rg: 3.5 nm 0 Dmax: 13.5 nm

Data validation


There are no models related to this curve.

Synchrotron SAXS data from solutions of P2X7 ballast domain in complex with Ca2+-calmodulin in 20 mM HEPES pH 7.5, 150 mM NaCl, 5 mM CaCl2, were collected on the EMBL P12 beam line at PETRA III (DESY, Hamburg, Germany) using a Pilatus 6M detector at a sample-detector distance of 3 m and at a wavelength of λ = 0.124 nm (I(s) vs s, where s = 4πsinθ/λ, and 2θ is the scattering angle). In-line size-exclusion chromatography (SEC) SAS was employed. The SEC parameters were as follows: A 35.00 μl sample at 14.6 mg/ml was injected at a 0.35 ml/min flow rate onto a GE Superdex 200 Increase 5/150 column at 10°C. 2880 successive 0.245 second frames were collected. The data were normalized to the intensity of the transmitted beam and radially averaged; the scattering of the solvent-blank was subtracted.

Calmodulin-1 (CaM)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   16.8 kDa
 
UniProt   P0DP23 (1-149)
Sequence   FASTA
 
P2X purinoceptor 7 (P2X7BD monomer)
Mol. type   Protein
Organism   Homo sapiens
Olig. state   Monomer
Mon. MW   24.6 kDa
 
UniProt   Q99572 (395-595)
Sequence   FASTA