The effect on amino acid transport of trypsin treatment of rat renal brush border membranes
| Autor: | Stanton Segal, Betty Y.L. Hsu, Constance M. Marshall, Susan M. Corcoran |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Male
Brush border Biophysics Biochemistry Aminopeptidase Leucyl Aminopeptidase Leucine medicine Animals Trypsin Proline Amino Acids chemistry.chemical_classification Kidney Medulla Microvilli Chemistry Vesicle Cell Membrane Membrane Proteins Biological Transport Rats Inbred Strains Cell Biology Alkaline Phosphatase Trypsinization Amino acid Rats Kinetics Glucose medicine.drug |
| Zdroj: | Biochimica et biophysica acta. 689(2) |
| ISSN: | 0006-3002 |
| Popis: | Trypsin treatment of isolated rat renal brush border membrane vesicles which preferentially releases l -leucine aminopeptides (EC 3.4.11.2) decreases their ability to take up a variety of amino acids under Na + -gradient conditions. Such treatment did not alter the osmotic properties of the vesicles nor affect their fragility. A linear correlation could be demonstrated between the l -leucine aminopeptidase activity of the membranes and the initial rate of uptake of l -leucine and l -proline. Velocity of uptake-concentration dependence studies with these substrates indicate that the major effect of trypsinization is to decrease the maximum velocity ( V max 1 ) of the low- K m high-affinity system with little effect on the V max 2 of the high- K m low-affinity transport process and no effect on the apparent Michaelis constants of either. Although the data indicate that l -leucine aminopeptidase activity and uptake of l -leucine and l -proline are affected in parallel, they should not be construed to imply a role of the enzyme in the transport process, especially in view of the global decrease in the uptake of various amino acids and sugars. |
| Databáze: | OpenAIRE |
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