Effect of red blood cell shape changes on haemoglobin interactions and dynamics : a neutron scattering study

• By using a combination of experimental neutron scattering techniques, it is possible to obtain a statistical perspective on red blood cell (RBC) shape in suspensions, and the inter-relationship with protein interactions and dynamics inside the confinement of the cell membrane. In this study, we examined the ultrastructure of RBC and protein-protein interactions of haemoglobin (Hb) in them using ultra-small-angle neutron scattering and small-angle neutron scattering (SANS). In addition, we used the neutron backscattering method to access Hb motion on the ns time scale and angstrom length scale. Quasi-elastic neutron scattering (QENS) experiments were performed to measure diffusive motion of Hb in RBCs and in an RBC lysate. By using QENS, we probed both internal Hb dynamics and global protein diffusion, on the accessible time scale and length scale by QENS. Shape changes of RBCs and variation of intracellular Hb concentration were induced by addition of the Na+-selective ionophore monensin and the K+-selective one, valinomycin. The experimental SANS and QENS results are discussed within the framework of crowded protein solutions, where free motion of Hb is obstructed by mutual interactions.

Subject headings

NATURVETENSKAP  -- Biologi -- Biofysik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biophysics (hsv//eng)

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Keyword

quasi-elastic neutron scattering

red blood cells

protein diffusion

small-angle neutron scattering

protein interactions

haemoglobin

haemoglobin

protein diffusion

protein interactions

quasi-elastic neutron scattering

red blood cells

small-angle neutron scattering

Publication and Content Type

ref (subject category)

art (subject category)