master's thesis
Kinetic characterization of amino acid oxidase from different sources and their application in the oxidation of l-methionine

Sanja Žeravica (2015)
Josip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Department of Process Engineering
Sub-department of Thermodynamics and Reaction Engineering
Metadata
TitleKinetička karakterizacija oksidaza aminokiselina iz različitih izvora i njihova primjena u oksidaciji L-metionina
AuthorSanja Žeravica
Mentor(s)Marina Tišma (thesis advisor)
Abstract
Oksidaze L-aminokiselina (L-AAO) su poznate po svojoj specifičnosti prema nizu različitih supstrata. U ovom radu su kinetički karakterizirani enzimi oksidaze L-aminokiselina iz triju različitih izvora. Korišteni su enzimi iz zmijskog otrova kobre roda Crotalus adamanteus, zmijskog otrova kobre Crotalus atrox i novi enzim iz bakterije Rhodococcus opacus. Kao supstrat je korišten L-metionin koji se u prisustvu enzima L-AAO oksidativno deaminira u odgovarajuću α-keto kiselinu uz nastanak vodikovog peroksida i amonijaka kao sporednih produkata. Prisustvo vodikovog peroksida je nepoželjno u reakcijskoj otopini, a za njegovo uklanjanje je korištena katalaza porijeklom iz goveđe jetre. Iz eksperimentalno određene ovisnosti specifične aktivnosti enzima o početnoj koncentraciji supstrata L-metionina, odnosno produkta, dobivenih metodom početnih brzina, nelinearnom regresijom su procijenjeni parametri Michaelis-Menteničinog izraza sva tri enzima, Vm i Km, kao i konstanta inhibicije produktom Ki. Biotransformacija L-metionina katalizirana oksidazama L-aminokiselina je provedena u kotlastom reaktoru bez dodatka katalaze te u ponovljenom kotlastom reaktoru s dodatkom katalaze. Postavljen je i validiran matematički model procesa biotransformacije L-metionina kataliziranog oksidazama L-aminokiselina.
Keywordsoxidase methionin mathematical model
Parallel title (English)Kinetic characterization of amino acid oxidase from different sources and their application in the oxidation of l-methionine
Committee MembersIvica Strelec
Marina Tišma
Natalija Velić
Mirela Planinić
GranterJosip Juraj Strossmayer University of Osijek
FACULTY OF FOOD TECHNOLOGY
Lower level organizational unitsDepartment of Process Engineering
Sub-department of Thermodynamics and Reaction Engineering
PlaceOsijek
StateCroatia
Scientific field, discipline, subdisciplineBIOTECHNICAL SCIENCES
Food Technology
Engineering
Study programme typeuniversity
Study levelgraduate
Study programmeFood Technology and Process Engineering
Academic title abbreviationdipl. ing.
Genremaster's thesis
Language Croatian
Defense date2015-02-27
Parallel abstract (English)
L-amino acid oxidases (L-AAO) are well known for their broad substrate specifity. In this work, three L-AAOs from different sources were kinetically characterized: two enzmyes from the snake venom of Crotalus adamanteus and Crotalus atrox, and a new enzyme from bacteria Rodococcus opacus. L-methionine was used as substrate. In the presence of L-AAO, L-methionine oxidizes to corresponding α-keto acid with production of hydrogen peroxide and ammonia as by-products. The presence of hydrogen peroxide in the reaction solution was unwanted and for its decomposition catalase from beef liver was used. Parameters of Michaelis-Mentens’s equation, Vm, Km and product inhibition constant, Ki were determined by non-linear regression from the experimentally observed dependence of the specific activity of enzyme on the initial concentration of substrate L-methionine and product (method of initial rates). Biotransformation of L-methionine catalysed by L-AAOs was carried out in batch reactor without the presence of catalase and in repetitive batch reactor with the addition of catalase. A mathematical model of L-methionine biotransformation process was developed and validated.
Parallel keywords (Croatian)oksidaza aminokiseline metionin matematički model
Resource typetext
Access conditionOpen access
Terms of usehttp://rightsstatements.org/vocab/InC/1.0/
URN:NBNhttps://urn.nsk.hr/urn:nbn:hr:109:331629
CommitterSanda Hasenay