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THE STEREO‐SPECIFICITY AND TEMPERATURE‐DEPENDENCE OF THE PERMEABILITY OF HUMAN ERYTHROCYTES TO ALDOSES
Author(s) -
Fisher R. B.,
Nimmo I. A.
Publication year - 1973
Publication title -
quarterly journal of experimental physiology and cognate medical sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0033-5541
DOI - 10.1113/expphysiol.1973.sp002200
Subject(s) - permeation , chemistry , saturation (graph theory) , limiting , xylose , membrane , dissociation (chemistry) , arabinose , biophysics , analytical chemistry (journal) , chromatography , biochemistry , organic chemistry , biology , fermentation , mechanical engineering , mathematics , combinatorics , engineering
Time‐courses have been determined between 2·0°C and 25·5°C for the uptake of D (+) glucose, D (+) xylose and L (+) arabinose by human erythrocytes. They can be explained by assuming uptake is governed by a mobile carrier of the Widdas type. Since at any temperature the three aldoses have the same maximum rate of permeation but different half‐saturation concentrations for the carrier, it is argued that they have a common carrier, and that the rate‐limiting step in permeation is the translocation across the membrane of the carrier or carrier‐aldose complex. Data are also given which suggest that α‐ and β‐glucose have different half‐saturation concentrations for the carrier.