Soluble and membrane-bound leucyl- and arginyl-aminopeptidase activities in subcellular fractions of young and adult rat brains.
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.
Ramírez
M
M
Departamento de Fisiología, Facultad de Medicina, Universidad del País Vasco, Bilbao, Spain.
Arechaga
G
G
García
S
S
Sánchez
B
B
Lardelli
P
P
Gandarias
J M
JM
D000626:Aminopeptidases / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000201:enzymology; D007931:Leucyl Aminopeptidase / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013347:Subcellular Fractions / Q000201:enzymology*; D013574:Synaptosomes / Q000201:enzymology
D000626:Aminopeptidases; D007931:Leucyl Aminopeptidase; C019721:aminopeptidase B