ΑΠΟΜΟΝΩΣΗ ΚΑΙ ΚΑΘΑΡΙΣΜΟΣ ΤΟΥ ΕΝΖΥΜΟΥ L-DOPA ΑΠΟΚΑΡΒΟΞΥΛΑΣΗ ΑΠΟ ΤΙΣ ΛΕΥΚΕΣ ΝΥΜΦΕΣ ΤΟΥ ΕΝΤΟΜΟΥ CERATITIS CAPITATA ΚΑΙ ΑΠΟ ΑΝΘΡΩΠΙΝΟ ΝΕΦΡΙΚΟ ΙΣΤΟ. ΣΥΓΚΡ...

L-DOPA DECARBOXYLASE IS A PYRIDOXAL PHOSPHATE-DEPENDENT ENZYME CATALYZING THE DECARBOXYLATION OF CERTAIN AROMATIC AMINO ACIDS TO THEIR RESPECTIVE AMINES. SINCE DOPAMINE IS INVOLVED IN MANY IMPORTANT METABOLIC PROCESSES PLAYING A CENTRAL ROLE IN THE PATHOGENESIS OF CERTAIN NEUROLOGICAL DISORDERS AND ON THE OTHER HAND O-DIPHENOLIC SUBSTANCES SUCH AS N-ACETYLODOPAMINE ARE INVOLVED IN SCLEROTIZATION OF INSECT CUTICLE, WE HAVE FOCUSED OUR ATTENTION ON THE PURIFICATION AND THE COMPARISON OF L-DOPA- DECARBOXYLASE FROM HUMAN AND INSECT TISSUES. USING STANDARD BIOCHEMICAL METHODOLOGY THE ENZYME HAS BEEN PURIFIED TO HOMOGENEITY FROM THE WHITE PREPUPAE LARVAE OF CERATITIS CAPITATA AS WELL AS FROM POST MORTEM HUMAN KIDNEY. COMPARISON OF THE RESULTS LEADS TO THE FOLLOWING CONCLUSION. 1. BOTH ENZYMES SHOW THE SAME MOLECULAR WEIGHT AND THE SAME DIMERIC STRUCTURE, CONSISTING OF TWO EQUAL SUBUNITS OF APPROXIMATELY 50.000. 2. ANTIBODIES RAISED IN RABBIT AGAINST THE PURIFIED HUMAN L-DOPA DECARBOXYLASE REACT WITH INSECT L-DOPA-DECARBOXYLASE AS JUDGED BY ELISA, AS WELL AS BY IMMUNOBLOTTING TECHNIQUES. IMMUNOPRECIPITATION OF THE ENZYME RESULTED IN A LOSS OF ACTIVITY CLEARLY SHOWING THAT ANTIBODIES AGAINST HUMAN L-DOPA DECARBOXYLASE ARE ALSO SPECIFIC FOR INSECT DOPADECARBOXYLASE. 3. HUMAN L-DOPA DECARBOXYLASE ACTIVITY IS HIGHLY DEPENDENTED ONTHE ADDITION OF EXOGENEOUS 5-PYRIDOXAL PHOSPHATE, REACHING A MAXIMAL 23-FOLD STIMULATION AT 400 MM PYRIDOXAL PHOSPHATE. INSECT L-DOPA DECARBOXYLASE ACTIVITY IS ONLY SLIGHTLY AFFECTED BY THE ADDITION OF EXOGENOUS 5-PYRIDOXAL PHOSPHATE. 4. THE EFFECT OF CATIONS ON ENZYMIC ACTIVITY IS COMPLETELY DIFFERENT IN THE TWO DECARBOXYLASES. HUMAN DECARBOXYLASE IS STRONGLY INHIBITED BY ZN2+, CU2+ AND HG2+ AND RATHER WEAKLY BY MG2+ AND CA2+. NONE OF THE ABOVE IONS EXHIBIT INHIBITORYEFFECT ON THE ENZYME PURIFIED FROM WHITE PREPUPAE. 5. HUMAN L-DOPA DECARBOXYLASE EXHIBITS A REMARKABLE SPECIFICITY TOWARDS L-DOPA AND AN AFFINITY FOR 5- HYDROXYTRYPTOPHAN. DOPA DECARBOXYLASE OF WHITE PREPUPAE SHOWS ABSOLUTE SPECIFICITY TOWARDS L-DOPA.

Grantor dc:publisher

Εθνικό και Καποδιστριακό Πανεπιστήμιο Αθηνών (ΕΚΠΑ)

Year dc:date

1990

Author dc:creator

• Μαππούρας, Δημήτριος

• AROMATIC AMINO ACID DECARBOXYLASE
• Biogenic amines
• Human tissues
• L-dopa decarboxylase
• Ανθρώπινοι ιστοί
• Αποκαρβοξυλάση αρωματικών αμινοξέων
• Αποκαρβοξυλάση της L-dopa
• Βιογενείς αμίνες
• Natural Sciences
• Biological Sciences
• Φυσικές Επιστήμες
• Βιολογία

Language dc:language

gre

Identifier

10.12681/eadd/1299

OAI identifier oai:identifier

oai:10442/1299