Soluble and membrane-bound leucyl- and arginyl-aminopeptidase activities in subcellular fractions of young and adult rat brains |
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| Authors: | M Ramírez G Arechaga S García B Sánchez P Lardelli J M Gandarias |
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| Affiliation: | Departamento de Fisiología, Facultad de Medicina, Universidad del País Vasco, Bilbao, Spain. |
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| Abstract: | The subcellular distribution of soluble and membrane-bound leucyl- and arginyl-aminopeptidase activities were analyzed in one and five month old rat brains using Leu- and Arg-2-naphthylamide as substrates. Both soluble leucyl- and arginyl-aminopeptidase activities showed the highest levels in the synaptosomal fraction in the two groups of rats. The highest levels of membrane-bound leucyl- and arginyl-aminopeptidase activities were found in the microsomal fraction in the two ages studied. There were no differences between the two ages in soluble leucyl- and arginyl-aminopeptidase activities. However, a significant decrease in both membrane-bound enzymatic activities was evidenced in the synaptosomal fraction of older rats. Developmental changes of these aminopeptidase activities in a determined subcellular localization, may reflect modifications in their effect on neuropeptides susceptible to be hydrolyzed in this particular location. |
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