dc.contributor.advisor | Strauss, Erick | en_ZA |
dc.contributor.author | Muneri, Ndivhuwo Olga | en_ZA |
dc.contributor.other | Stellenbosch University. Faculty of Science. Dept. of Biochemistry. | en_ZA |
dc.date.accessioned | 2012-11-28T15:08:09Z | en_ZA |
dc.date.accessioned | 2012-12-12T08:19:37Z | |
dc.date.available | 2012-11-28T15:08:09Z | en_ZA |
dc.date.available | 2012-12-12T08:19:37Z | |
dc.date.issued | 2012-12 | en_ZA |
dc.identifier.uri | http://hdl.handle.net/10019.1/71972 | |
dc.description | Thesis (MSc)--Stellenbosch University, 2012. | en_ZA |
dc.description.abstract | ENGLISH ABSTRACT: Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis,
utilizes mycothiol (MSH) as the major low molecular weight thiol to protect itself
against oxidative stress and thereby to ensure its growth and survival. MSH is a
pseudo-disaccharide molecule that contains an α(1→1) glycosidic bond, and is
biosynthesised in five enzymatic steps involving the enzymes MshA, MshA2, MshB,
MshC and MshD. Owing to the essentiality of MSH to M. tuberculosis, various
studies have focused on the MSH biosynthetic and other MSH-dependent enzymes
viewed as potential drug targets for the development of antituberculosis agents. In
the course of this study two practical challenges affecting the development of
inhibitors of one the MSH biosynthesis pathway enzyme, MshB, were addressed.
These challenges entail the lack of a high-throughput continuous assay to determine
MshB activity, and the poor availability of the natural and alternative MshB
substrates. In this study an alternate MshB substrate was characterized and shown
to undergo a rearrangement reaction upon deactylation, which allowed the
development of a new continuous assay for MshB activity that uses DNTB (Ellman’s
reagent). In addition, three new α-thioglycoligases were created from the α-Nacetylglucosaminidase
of Clostridium perfringens. These enzymes showed potential as biocatalysts that can be used for the enzymatic synthesis of thioglycoside-based
alternative substrates of MshB. | en_ZA |
dc.description.abstract | AFRIKAANSE OPSOMMING: Mycobacterium tuberculosis, die organisme wat tuberkulose veroorsaak, maak
gebruik van mikotiol (MSH) om homself te beskerm teen oksidatiewe stres en
sodoende sy groei en oorlewing te verseker. MSH is ʼn pseudo-disakkaried molekule
met ʼn α(1→1) glikosidiese binding, en word in vyf ensimatiese stappe
gebiosintetiseer deur die ensieme MshA, MshA2, MshB, MshC en MshD. Weens die
noodsaaklikheid van MSH vir M. tuberculosis het verskeie vorige studies gefokus op
die MSH biosintetiese en ander MSH-afhanklike ensieme as potensiële teikens vir
die ontwikkeling van antituberkulose middels. In die loop van hierdie studie is twee
praktiese uitdagings wat die ontwikkeling van inhibitors van een van die MSH
biosintetiese ensieme, MshB, bemoeilik, aangespreek. Hierdie uitdagings behels die
gebrek aan 'n geskikte hoë-deurvloei kontinue essaï vir MshB aktiwiteit, en die lae
beskikbaarheid van die natuurlike en alternatiewe MshB substrate. In hierdie studie is
alternatiewe MshB substrate gekarakteriseer en is daar gewys dat dit ʼn
herrangskikkingsreaksie ondergaan na deasetilering, wat die ontwikkeling van ʼn
nuwe kontinue essaï vir MshB aktiwiteit wat gebruik maak van DTNB (Ellman se
reagens), moontlik gemaak het. Verder is drie nuwe α-tioglikoligases ontwikkel van
die ensiem α-N-asetielglukosaminidase van Clostridium perfringens. Hierdie ensieme
toon potensiaal as biokataliste wat gebruik kan word in die ensiematiese sintese van tioglikosied-gebaseerde alternatiewe substrate van MshB. | af_ZA |
dc.format.extent | 98 pages : illustrations | en_ZA |
dc.language.iso | en_ZA | en_ZA |
dc.publisher | Stellenbosch : Stellenbosch University | en_ZA |
dc.rights | Stellenbosch University | en_ZA |
dc.subject | Mycothiol pathway enzyme | en_ZA |
dc.subject | MshB -- Biocatalytic preparation | en_ZA |
dc.subject | MshB -- characterisation | en_ZA |
dc.subject | UCTD | en_ZA |
dc.title | Biocatalytic preparation and characterization of alternative substrate of MshB, a mycothiol pathway enzyme | en_ZA |
dc.type | Thesis | en_ZA |