Release of Vitamin B12-Binding Protein from Isolated Rat Liver Perfused with a Synthetic Medium

1976 ◽  
Vol 96 (4) ◽  
pp. 500-505 ◽  
Author(s):  
Vera Nováková ◽  
Ragnhild Gullberg
Keyword(s):  
Vitamin B12 ◽  
Rat Liver ◽  
Binding Protein ◽  
Synthetic Medium ◽  
Isolated Rat Liver ◽  
Isolated Rat

scholarly journals Protein-mediated uptake of vitamin B12 by isolated mitochondria

Blood ◽  
1976 ◽  
Vol 47 (6) ◽  
pp. 923-930 ◽  
Author(s):  
RA Gams ◽  
EM Ryel ◽  
F Ostroy
Keyword(s):  
Vitamin B12 ◽  
Rat Liver ◽  
Mitochondrial Respiration ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Isolated Mitochondria ◽  
Isolated Rat

Abstract Protein-mediated B12 uptake by isolated rat liver mitochondria has been shown to be enhanced by plasma transcobalamin (TC-II) but not by salivary R binder in vitro. The process is enhanced by calcium and depends on active mitochondrial respiration. Following uptake, cyanocobalamin is converted to adenosyl and methylcobalamins and released from the mitochondria. TC-II appears to be required for both cellular and mitochondrial uptake of vitamin B12.

scholarly journals Protein-mediated uptake of vitamin B12 by isolated mitochondria

Blood ◽  
1976 ◽  
Vol 47 (6) ◽  
pp. 923-930
Author(s):  
RA Gams ◽  
EM Ryel ◽  
F Ostroy
Keyword(s):  
Vitamin B12 ◽  
Rat Liver ◽  
Mitochondrial Respiration ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Isolated Rat Liver ◽  
Isolated Mitochondria ◽  
Isolated Rat

Protein-mediated B12 uptake by isolated rat liver mitochondria has been shown to be enhanced by plasma transcobalamin (TC-II) but not by salivary R binder in vitro. The process is enhanced by calcium and depends on active mitochondrial respiration. Following uptake, cyanocobalamin is converted to adenosyl and methylcobalamins and released from the mitochondria. TC-II appears to be required for both cellular and mitochondrial uptake of vitamin B12.

The uptake of R-type cobalamin-binding protein by isolated rat liver cells

1982 ◽  
Vol 720 (2) ◽  
pp. 203-210 ◽  
Author(s):  
J. Lindemans ◽  
E.J.M. de Jongh ◽  
F.C.M. Brand ◽  
M. Schoester ◽  
J. Van Kapel ◽  
...  
Keyword(s):  
Rat Liver ◽  
Binding Protein ◽  
Liver Cells ◽  
Isolated Rat Liver ◽  
Rat Liver Cells ◽  
Isolated Rat

BINDING OF L-TRIIODOTHYRONINE TO ISOLATED RAT LIVER AND KIDNEY NUCLEI UNDER VARIOUS CIRCUMSTANCES

1976 ◽  
Vol 81 (1) ◽  
pp. 82-95 ◽  
Author(s):  
R. Docter ◽  
T. J. Visser ◽  
J. T. Stinis ◽  
N. L. van den Hout-Goemaat ◽  
G. Hennemann
Keyword(s):  
Rat Liver ◽  
Binding Sites ◽  
Association Constant ◽  
Binding Capacity ◽  
Binding Protein ◽  
Isolated Rat Liver ◽  
Relative Affinity ◽  
Liver And Kidney ◽  
Maximal Binding ◽  
Isolated Rat

ABSTRACT Triiodothyronine (T3) is specifically bound by nuclei from rat liver and kidney. Binding of T3 at 37°C reaches its maximum at 30 min. In the presence of EDTA (to remove Mg2+) T3 binds to a class of binding sites with an estimated equilibrium association constant (Ka) of 3.3 × 1010 m−1 and a maximal binding capacity (MBC) of 3.8 fmol T3/100 μg DNA. In the presence of MgCl2 T3 binds to a second class of binding sites with an estimated Ka of 4.8 × 108 m−1 and a MBC of 123 fmol/100 μg DNA. Among the analogues tested, binding - relative to T3 - of D-T3, triiodothyroacetic acid and desamino-T3 is the same for both classes of binding sites, but relative affinity of thyroxine, D-T4, tetraiodothyroacetic acid and desamino-T4 is 2.5 to 6 times higher for the second class of binding sites than for the first class. The presence of a cytosol binding protein is not a prerequisite for binding of T3 to the nucleus.

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