An aminopeptidase activity from porcine kidney that hydrolyzes oxytocin and vasopressin: purification and partial characterization

Itoh, Chie; Nagamatsu, Akio

doi:10.1016/0304-4165(94)00151-m

Cited by 26 publications

(15 citation statements)

References 18 publications

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“…Over the time period of observation (10 min), PKLAP activity was the highest at 31 °C, and slowly decreased at higher temperatures. These results are consistent with previous observations [22]. Because the fluorescence of the amino-pyridines ( III to V ) is optimal around pH 8.0 [12], we decided to run the enzymatic activity at pH 8.0 (0.1 M sodium phosphate buffer) at 31 °C.…”

Section: Resultssupporting

confidence: 90%

Novel and highly sensitive fluorescent assay for leucine aminopeptidases

Huang

Tanaka

Hammock

et al. 2009

Analytical Biochemistry

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L-Leucine aminopeptidases (LAPs) are implicated in the progress of many pathological disorders, and play some regulatory roles in tumor cell proliferation, invasion and/or angiogenesis. Thus, LAPs could become not only new diagnostic or prognostic biomarkers, but also have potential as novel molecular targets for the treatment of several cancers. Highly sensitive assays are critical for early detection of changes in LAP activity and for screening potent LAP inhibitors. In this study, we developed a novel and highly sensitive fluorescent assay for LAPs based on substituted aminopyridines as fluorescent reporters. This assay was at least 100 and 20 fold more sensitive than commercial colorimetric or fluorescent LAP substrates, respectively. We also showed that this assay was a useful tool to monitor LAP activities in extracts from cancer cell lines, as well as for the high throughput screening of inhibitors, which could lead to new cancer treatments.

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Section: Resultssupporting

confidence: 90%

Novel and highly sensitive fluorescent assay for leucine aminopeptidases

Huang

Tanaka

Hammock

et al. 2009

Analytical Biochemistry

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“…28 CysAP activity has been reported to hydrolyse oxytocin and vasopressin. 29 Although several peptides have been proposed as susceptible substrates for pGluAP in vitro, the most important endogenous substrate may be the hypophysiotropic hormones TRH 30 and GnRH, 31 although neurotensin and bombesin have also been reported to be substrates. 31 LeuAP may hydrolyse enkephalins, 16 dinorphins 32 and substance P. 33 TyrAP has been described as an enkephalin aminopeptidase.…”

Section: Discussionmentioning

confidence: 99%

Effects of exogenous fatty acids and cholesterol on aminopeptidase activities in rat astroglia

Ramírez‐Expósito

García

Mayas

et al. 2002

Cell Biochemistry & Function

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Several studies have addressed the interaction between fatty acids and lipids with central nervous system peptides. Because aminopeptidases (AP) are involved in the regulation of neuropeptides, this work studies several AP expressed in cultured astroglia, after exogenous addition of oleic and linoleic fatty acids and cholesterol to the culture medium. Alanyl-AP, arginyl-AP, cystyl-AP, leucyl-AP, tyrosyl-AP and pyroglutamyl-AP activities were analysed in whole cells using the corresponding aminoacyl-beta-naphthylamides as substrates. Oleic acid inhibits alanyl-AP, cystyl-AP and leucyl-AP activities, whereas linoleic acid inhibits alanyl-AP, arginyl-AP and tyrosyl-AP activities. Neither oleic acid nor linoleic acid modifies pyroglutamyl-AP activity. In contrast, cholesterol increases arginyl-AP, cystyl-AP, leucyl-AP, tyrosyl-AP and pyroglutamyl-AP activities, although it does not modify alanyl-AP activity. The changes reported here suggest that oleic and linoleic fatty acids and cholesterol can modulate peptide activities via their degradation route involving aminopeptidases; each of them being differentially regulated.

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“…Subsequently, Tsujimoto et al [34] purified a human placental LeuAP (EC 3.4.11.3) that hydrolyzed oxytocin, vasopressin and angiotensin III, and concluded that P-LeuAP and CysAP activities were shared by the same molecule. However, Itoh and Nagamatsu [35] purified an aminopeptidase that hydrolyzed oxytocin and vasopressin, with properties different from LeuAP (EC 3.4.11.1), AlaAP (EC 3.4.11.2) and P-LeuAP (EC 3.4.11.3). This enzyme hydrolyzed L -Cys-p -nitroanilide with the highest specificity.…”

Section: Discussionmentioning

confidence: 99%

Stress Influences Brain Enkephalinase, Oxytocinase and Angiotensinase Activities: A New Hypothesis

et al. 2009

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Brain enkephalin and oxytocin are anxiolytic agents involved in the response mechanism to stress. Degrading enzymes such as enkephalinase and oxytocinase could also be associated with this response. The effect of acute immobilization stress on enkephalinase and oxytocinase activities was determined in the soluble and membrane fractions of the medial prefrontal cortex, hippocampus and amygdala using alanyl- and leucyl-beta-naphthylamide as substrates, the latter in the presence and absence of 20 mML-methionine. No change in aminopeptidase activities was observed in the prefrontal cortex of stressed rats. In contrast, enkephalinase activity decreased in the soluble fraction of the hippocampus but increased in the membrane fraction. In the amygdala, soluble oxytocinase and membrane enkephalinase activities decreased in stressed animals. These results show that acute immobilization stress affects differentially enkephalinase and oxytocinase activities depending on the fraction and brain region analyzed. A reduction in the activity of soluble enkephalinase in the hippocampus and soluble oxytocinase as well as membrane enkephalinase in the amygdala may suggest higher availability/longer action of enkephalin and oxytocin at these locations. This may explain the relative importance of these enzymatic activities in the anxiolytic properties proposed for enkephalins and oxytocin in the hippocampus and amygdala during stress conditions. This interpretation is not applicable to membrane enkephalinase activity in the hippocampus. However, alanyl-beta-naphthylamide hydrolyzing activity not only measures enkephalinase activity, it also reflects the angiotensinase-induced metabolism of angiotensin III to angiotensin IV. Therefore, our results may also mirror an increase in the formation of Ang IV in hippocampus and a decrease in the amygdala in acute stress. In conclusion, aminopeptidase activities in the hippocampus and amygdala may affect enkephalin, oxytocin and angiotensin III metabolism during acute immobilization stress and therefore be involved in the anxiolytic response.

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An aminopeptidase activity from porcine kidney that hydrolyzes oxytocin and vasopressin: purification and partial characterization

Cited by 26 publications

References 18 publications

Novel and highly sensitive fluorescent assay for leucine aminopeptidases

Novel and highly sensitive fluorescent assay for leucine aminopeptidases

Effects of exogenous fatty acids and cholesterol on aminopeptidase activities in rat astroglia

Stress Influences Brain Enkephalinase, Oxytocinase and Angiotensinase Activities: A New Hypothesis

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