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  <doc>
    <id>886</id>
    <completedYear/>
    <publishedYear>2021</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst/>
    <pageLast/>
    <pageNumber>95</pageNumber>
    <edition/>
    <issue/>
    <volume/>
    <type>bachelorthesis</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2021-07-27</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">The impact of light on the activity of PLP-dependent enzymes</title>
    <abstract language="eng">Enzymes are important biological catalyst with high chemo-, regio-, and stereoselectivity. Among  the different classes of enzymes, PLP-dependent enzymes are of special interest for industrial  biocatalysis due to their wide range of applications. As it is known, that the cofactor PLP is instable  under light exposure, the aim of this thesis was to investigate, whether this affects the activity of  PLP-dependent enzymes. Therefore, six PLP-dependent enzymes consisting of four amine transaminases from Chromobacterium violaceum (Cv2025), Vibrio fluvialis (VfTA), Bacillus megaterium (BmTA), and an eleven rounds mutated Arthrobacter sp. (AsTAmut11) and two lysine decarboxylases from Escherichia coli (EcLDC) and Selenomonas ruminantium (SrLDC) were analyzed in different natural and artificial light setups. Cv2025, BmTA, and SrLDC have approximately 40%, 30%, and 50% reduced activity in the light compared to dark condition respectively. EcLDC shows highest inactivation of about 90%. VfTA is stable in HEPES buffer but has 50% inactivation in TRIS and KPi buffer. AsTAmut11 is a special case, where there is no inactivation seen in light condition, but the enzyme gains about 30% and more activity over the course of 6 h. This was seen in the dark and light condition. Conclusively, not only light itself effects the enzyme activity, but also the reaction conditions in combination with the light. The whole study proves, that it can be of immense importance to protect some PLP-dependent enzymes from light. Not only during the reaction, but also during the purification procedure. To mediate proper analysis of LDCs, a new photometric assay was developed using the indicator p� nitrophenol, in contrast to the available work intensive HPLC analysis. This indicator covers pH range from 6 to higher than 8 and enables sensitive analysis of cadaverine concentration with high sensitivity below 1 mM. With optimized photometric cadaverine calibration, the photometric assay is a reasonable alternative to HPLC based analysis.</abstract>
    <identifier type="urn">urn:nbn:de:hbz:1383-opus4-8864</identifier>
    <enrichment key="opus.source">publish</enrichment>
    <licence>CC BY-ND 4.0 International - Namensnennung-Keine Bearbeitungen</licence>
    <author>David Limanhadi Nugroho</author>
    <collection role="institutes" number="">Fakultät Life Sciences</collection>
    <thesisPublisher>Hochschule Rhein-Waal</thesisPublisher>
    <thesisGrantor>Hochschule Rhein-Waal</thesisGrantor>
    <file>https://opus4.kobv.de/opus4-rhein-waal/files/886/Nugroho_David_Bachlorthesis.pdf</file>
  </doc>
</export-example>
