Temperature transitions of protein properties in human red blood cells

Human red blood cells (RBC) undergo a sudden change from blocking to passing through 1.3 +/- 0.2-mu m micropipettes at a transition temperature (T-c) of 36.4 degrees C, For resealed RBC ghosts this transition occurs at 28.3 degrees C (T-g). These findings are attributed to an elastomeric transition of hemoglobin from being gel-like to a fluid and to an elastomeric transition of membrane proteins such as spectrin, Spectrin shows a uniform distribution along the aspirated RBC tongue above T-g in contrast to the linear gradient below T-g.