SYNOPSIS Some carbohydrates inhibited glucose and fructose transport in Trypanosoma gambiense. Glucose transport was inhibited by glycerol, mannose, 2‐deoxy‐D‐glucose, glucosamine and N‐acetylglucosamine. Fructose transport was inhibited by glucose, glycerol, mannose, glucosamine and N‐acetylglucosamine. Glucosamine transport appeared to be a mediated process and had a Km of 1.20 mM and a Vmax of 28.5 μM glucosamine/g dry wt/2 min. Glucosamine absorption was competitively inhibited by glucose, fructose and N‐acetylglycosamine. N‐Acetylglucosamine appeared to enter by passive diffusion. Reciprocal inhibition experiments suggested that glucosamine entered entirely via the “fructose site.” Specificity of sugar transport in T. gambiense differs from that of other organisms.

Under the above title, D. Van Nostrand Company, Inc. will shortly publish the book from which the following article is excerpted. Dr. Southworth is one of the leading authorities on waveguides and was one of the first to foresee the great usefulness that this form of transmission might offer. The editors of the Bell System Technical Journal are grateful for permission to publish here parts of the preface and the historical introduction and chapter 6 in its entirety.

SYNOPSIS. The uptake of 14C‐labeled carbohydrates by Trypanosoma gambiense was studied. Glucose, mannose, glycerol, 2‐deoxyglucose and fructose were rapidly absorbed by the parasite, and all had saturation kinetics. The glucose analog 3‐O‐methylglucose was not taken up by T. gambiense. Competitive inhibition experiments indicate that there are 2 transport loci for the tested substrates. It is suggested that there is a “glucose site” thru which glucose, mannose and glycerol, but not fructose, are transported and a “fructose site” thru which only fructose is transported. The specificity of the glucose‐transporting mechanism appears to differ from those of other animals.

No abstract

No abstract