Showing papers on "Cobalamin transport published in 1980"
TL;DR: Methylmalonyl-CoA mutase, one of two known cobalamin-dependent enzymes present in mammalian tissues, has been isolated from 2.5 kg of human placenta utilizing affinity chromatography on 5'-deoxyadenosylcobalamination-Sepharose as the major purification step.
38 citations
TL;DR: Results suggest that there may be a close link between TC II-mediated cobalamin transport and intracellular synthesis of adenosylcobalamin (Ado-Cbl).
Abstract: Cobalamin metabolism has been investigated in a new case of transcobalamin II (TC II) deficiency. Using the chromatobioautographic technique, an abnormal distribution of cobalamins was detected in the child's erythrocytes and reduced synthesis of adenosylcobalamin but not of methylcobalamin in cultured fibroblasts. These results suggest that there may be a close link between TC II-mediated cobalamin transport and intracellular synthesis of adenosylcobalamin (Ado-Cbl).
10 citations
TL;DR: The ileum from gastrectomized rats is shown to contain the intrinsic factor receptor, which disproves the hypothesis that the ileal receptor is the transport protein itself, internalized in the cell membrane.
Abstract: The specific cobalamin transport proteins chemically resemble their receptors in cell membranes. They are therefore assumed to have developed as gene duplications of their receptors. Since the transport proteins have a great tendency to form oligomers, their attachment to their receptors seems to be analogous to the formation of an oligomer. However, the theoretical possibility exists that the receptor is the transport protein itself, internalized in the cell membrane. The ileum from gastrectomized rats is here shown to contain the intrinsic factor receptor, which disproves this hypothesis about the ileal receptor. Free intrinsic factor was found in extracts from control rat intestinal mucosa but not in that of gastrectomized animals.
3 citations