Acetaldehyde inhibits serum aminopeptidases.
Aminopeptidase A (APA)- and aminopeptidase M (APM)-like activity were assayed in Moni-Trol ES with L-alpha-aspartyl-beta-naphthylamide and L-alanyl-beta-naphthylamide, respectively. Upon preincubation of the serum with 89.4, 223.5, and 447 mM acetaldehyde at room temperature for 30 min, a reduction in 26.8%, 55.3%, and 75.8% aminopeptidase A activity was observed. Similarly, aminopeptidase M activity was reduced by 26.5% and 53.1% upon preincubation with 223.5 and 447 mM acetaldehyde. Ethanol at 84.9, 212.3, and 427.9 mM did not significantly affect the enzymic activity. Because aminopeptidase A and aminopeptidase M also degrade the pressor substance, angiotensin II, it is suggested that inhibition of aminopeptidase A- and aminopeptidase M-like activity by acetaldehyde, the product of ethanol metabolism, may lead to higher levels of circulating angiotensin II and, consequently, hypertension, in alcoholics. The hydrolysis of lysine-p-nitroanilide, an aminopeptidase B substrate, was also inhibited upon addition of acetaldehyde to Moni-Trol ES serum.
Brecher
A S
AS
Department of Chemistry, Bowling Green State University, OH 43403, USA.
Stauffer
R
R
Knight
J
J
D000079:Acetaldehyde / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000626:Aminopeptidases / Q000037:antagonists & inhibitors* / Q000097:blood; D000804:Angiotensin II / Q000378:metabolism; D002492:Central Nervous System Depressants / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D043384:Glutamyl Aminopeptidase; D063208:Methionyl Aminopeptidases; D008969:Molecular Sequence Data
D002492:Central Nervous System Depressants; D000804:Angiotensin II; D000431:Ethanol; D000626:Aminopeptidases; D063208:Methionyl Aminopeptidases; D043384:Glutamyl Aminopeptidase; D000079:Acetaldehyde