Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The specificity of bovine spleen cathepsin B2 has been investigated by means of some natural oligo- and polypeptides, i.e. glucagon, melittin, insulin A and B chain, bradykinin, angiotensin I and II, oxytocin ACTH, clupein and salmin. The enzyme is primarily a carboxypeptidase which hydrolyzes peptide linkages of most amino acids common to proteins. In addition, cathepsin B2 displays amidase and esterase activity without requiring a free carboxyl group. The main pH optimum is between 4 and 5, in some cases higher.
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PMID:On the specificity of bovine spleen cathepsin B2. 1 11

An identical cytochrome b561 was found to be an integral component of both chromaffin vesicles from adrenal medulla and neurosecretory vesicles from posterior pituitary by spectrophotometric and immunological techniques. The neurosecretory vesicles had 6.8 micrograms of cytochrome/mg of membrane protein versus 69 micrograms/mg in chromaffin vesicles. This cytochrome was also immunologically detected in various regions of bovine brain and was immunologically distinct from the cytochrome found in serotonin-containing vesicles from platelets. Dopamine beta-hydroxylase involved in the biosynthesis of catecholamines was not present in neurosecretory vesicles, suggesting an alternative functional role for the cytochrome in these vesicles. Neurosecretory vesicles do contain a mixed function oxidase (peptidyl alpha-amidase) which appears to be involved in alpha-amidation of the carboxyl termini of vasopressin and oxytocin. We suggest that cytochrome b561 in the two vesicles may be functionally associated with different ascorbic acid-dependent, copper-containing mixed function oxidases: dopamine beta-hydroxylase and peptidyl alpha-amidase.
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PMID:An identical cytochrome b561 is present in bovine adrenal chromaffin vesicles and posterior pituitary neurosecretory vesicles. 671 27

Adenosine deaminase in the hypothalamic tuberomammillary nucleus and median eminence of rat and mouse brains was investigated with two different antibodies generated against the enzyme derived from either calf or mouse. Both antibodies labelled neurons in the tuberomammillary nucleus and, as determined in rat, they immunolabelled the same neurons. In the median eminence, immunopositive fibres and terminals were detected with anti-mouse adenosine deaminase in both rat and mouse, while no such staining was seen in either species with antibody against the calf enzyme. These fibres were most concentrated in the external median eminence, had a more restricted distribution than those containing either galanin or tyrosine hydroxylase and only partially overlapped with oxytocin-positive fibres. By electron microscopy, adenosine deaminase was found in terminals containing both small, clear vesicles with diameters of 35 to 45 nm and large dense-core vesicles with diameters of 100 to 140 nm. Preadsorption of antibodies with purified enzyme derived from the species against which they were directed eliminated all staining in rat, while antibody adsorptions across species were less effective. Preadsorption of anti-mouse adenosine deaminase antibody with the mouse deaminase led to increased labelling in mouse median eminence, suggesting an interaction between tissue components and antibody-linked enzyme. Tests for the presence of adenosine deaminase-complexing protein (CD26) with an antibody against this protein gave positive labelling in the median eminence of both species and this labelling was co-distributed with that seen for adenosine deaminase. These results confirm the expression of adenosine deaminase in restricted populations of neurons in rodent brain as revealed with a novel antibody, suggest the presence of a distinct form or localization of the enzyme in the median eminence, and raise the possibility that it contributes, perhaps along with CD26, to purinergic regulation of hormone secretion in this structure.
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PMID:Adenosine deaminase in rodent median eminence: detection by antibody to the mouse enzyme and co-localization with adenosine deaminase-complexing protein (CD26). 878 62