Esterase activity of synthetic fragments of human adrenocorticotrophic hormone.
The anterior pituitary hormone adrenocorticotrophin (ACTH) has been extensively studied in terms of structure-function relationships and in vivo and in vitro activities of different synthetic fragments of ACTH have been characterized. Here we describe the ability of synthetic fragments of ACTH to hydrolyze a fluorogenic esterase substrate 4-methylumbelliferyloleate (MUBO). The measured esterase activities (in mumol 4-MU mol-1 s-1) were 79.7 for ACTH1-13, 385.9 for ACTH3-18, 503.0 for ACTH1-19, 1249.9 for ACTH1-24 D-ser3, and 1350 for ACTH1-24. Although the significance of the observed esterase activities in the actual molecular mechanisms of action of ACTH remains to be established it is worth noticing that the esterase activities of the different ACTH fragments closely parallel their reported ability to activate the brain lipase as well as their in vivo ability to induce steroidogenesis in adrenal cortex.
Eklund
K K
KK
Department of Medical Chemistry, University of Helsinki, Finland.
Vainio
P
P
Virtanen
J A
JA
Kinnunen
P K
PK
D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism*; D004950:Esterases / Q000378:metabolism*; D006801:Humans; D006867:Hydrolases / Q000378:metabolism; D006923:Hymecromone / Q000031:analogs & derivatives; D007700:Kinetics; D010446:Peptide Fragments / Q000378:metabolism; D013050:Spectrometry, Fluorescence / Q000379:methods
D010446:Peptide Fragments; C023520:4-methylumbelliferyl oleate; D006923:Hymecromone; D000324:Adrenocorticotropic Hormone; D006867:Hydrolases; D004950:Esterases