Abstract
1-anilino-naphthalene-8 -sulfonate (ANS) fluorescence measurements have revealed that red blood cell membrane of the Rhnull type undergoes a transition at about 16 °C. In contrast, viscosity measurements of the extracted membrane lipids showed the usually observed transition at about 18 °C.
Lower values of titratable sulfhydryl (SH) groups were observed in Rhnull membrane using 5,5′-dithiobis-(2-nitro-benzoic-acid) (Nbs2). In contrast, disulfide bonds in Rhnull membrane were estimated to be about 3 times the value of the controls.
Spin labeling experiments using 2-(3-carboxypropyl)-4, 4 dimethyl-2-tridecyl 3-oxazolidinyl-oxyl were carried out with phospholipase A2 modified membranes. The mobile part of the spectra was significantly increased on the Rhnull membrane.
In the presence of ᴅ-glucose, infrared spectrometry showed a larger reduction of the intensity of the POO-band in Rhnull membrane.
In contrast to controls, binding of the reagent diethylpyrocarbonate resulted in no significant changes of the Rhnull membrane as determined by electron spin resonance (ESR) measurements.
ᴅ-glucose transport activity was found to be at the upper level of a group of Rh positive and Rh negative persons.
It is suggested that the intensity of the polar protein-lipid interaction is reduced in Rhnull membrane.