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Site directed Mutagenesis of Carbohydrate Binding Module Family 40 (CBM40) domain from Vibrio cholerae Non-01 sialidase
No full textThe location of sialic acid at the termini of various carbohydrate complexes often exploited by microbial
pathogens (influenza and parainfluenza viruses) to bind and gain entry to the host cell during the initial stages
of pathogenesis thus mediating specific role in human health and diseases. Carbohydrate-binding modules
(CBMs) help target the main enzyme to appropriate substrates and increase their catalytic efficiency.
However, proteins with weak binding affinity often use site-directed mutagenesis approach to enhance protein
affinity via an avidity effect. In this study, a wild-type Family 40 Carbohydrate Binding Module (WT-CBM40)
was genetically modified by site-directed mutagenesis to form a stable mutant CBM40 (M-CBM40) to
improve domain affinity towards sialic acid. In this study, a gene encoding for Family 40 Carbohydrate
Binding Module (CBM40) from Vibrio cholerae Non-O1 sialidase was cloned in pET22b(+) and successfully
expressed in E. coli BL21 (DE3) strain. The CBM40 encodes for 195 amino acids with 585 bp of nucleotide
sequence. Mutation of Thr200 to Asn200 was successfully performed using the QuikChange II Site-Directed
Mutagenesis Kit (Agilent). This study also deals with the generation of a 3-D model of the mutant CBM40
with 2w68.1.A as a template. The validation of mutant CBM40 brings to 0.99 Global Model Quality
Estimation (GMQE) scores and 1.14 Quality Model Energy Analysis (QMEAN) Z-scores. Both results
indicate the reliability of the mutant model. The analysis visualization of mutant CBM40 by UCSF Chimera
proved by MatchMaker sequence alignment score of 1005.9 and RMSD score of 0.08 Å demonstrated both
wild type CBM40 and mutant CBM40 structure were closely related. The results gained by Arpeggio web
server revealed that the affinity of mutant CBM40 higher than wild type CBM40. For the protein expression
study, mutant CBM40 was successfully expressed at 25 ˚C when induced with 1 mM IPTG whereas for
wild-type CBM40 was successfully expressed at 18 ˚C, the best IPTG concentration used was 1.5 mM.
Maximum expression was achieved at 20 hours after post-induction time. SDS-PAGE analysis of the
expressed wild-type and mutant CBM40 proteins displayed a protein band with a molecular mass of 21 kDa.
This contruct has a big potential to be developed as therapeutics agent especially as biologics to prevent
harmful pathogens gain entry through sialic acid binding present on human and mammalian cell surfaces The
optimum characterization conditions established would further lead to the discovery of the true potential of
CBM40 protein in enhancing substrate binding affinity, protein-carbohydrate recognition which underpins its
broad applications in biotechnology and protein engineering fields
Model kreativiti pengajaran guru bahasa arab di Malaysia
No full textThis study investigated the model of creativity of Arabic language teaching
in Malaysia. Technological Pedagogical Content Knowledg (TPACK) has
been made as the main model in this study. This model is based on a
study which consisted of 530 Arabic language teachers from 7,309
teachers in Peninsular Malaysia including Sabah and Sarawak.
Quantitative research methods were used and random sampling were
carried out for the collection of data. The data were analyzed using the
Statistical Package for Social Science (SPSS). The findings of this study
explained that the model of teaching creativity needs to focus on
Pedagogical Knowledge, Technological Pedagogical Content Knowledge,
Pedagogical Content Knowledge and Technological Pedagogical
Knowledge. In conclusion, the findings clearly indicate that the Arabic
language teachers in Malaysia need to focus on the elements that have
been stated to develop an excellent knowledge in creativity of teaching
Influence of spatial variation on the physicochemical properties and minerals content of stingless bee honey (Heterotrigona itama) in Terengganu Malaysia
No full textThe growing interest in the usage of stingless bee honey as functional food proceeds from its composition,
which has been associated with bio-medicinal properties. However, the composition of honey is varies
depended on the types and origin of bees’ food; which are flower nectar and plant honeydew. Thus, this study
was done to investigate the influence of spatial variation on the physichochemical and minerals content of
stingless bee honey in Terengganu. Honey produced by Heterotrigona itama were collected from four stingless
bee apiary which are Banggol Peradong, Kubang Jela, Benting Lintang and Tembila. All those location
surrounded with different plant diversity; Banggol Peradong with fruits orchard, Kubang Jela with ornamental
plants, Benting Lintang with coconut trees and Tembila with gelam trees. The physicochemical properties,
antioxidant activity, total phenolic compounds, total flavonoid compound and minerals of stingless bee honey
were evaluated. Results obtained shows that the pH of honey at all locations were acidic, ranging from
3.31-3.54. Honey from Benting Lintang is the sweetest (71.69 ± 0.075°Brix) followed Tembila (70.51 ± 0.028°
Brix), Kubang Jela (69.77 ± 0.060°Brix) and Banggol Peradong (69.40 ± 0.052°Brix). Moisture content of
honey ranged from 32.11 to 33.13% and electrical conductivity of 0.65 to 1.46mScm-1 which show significant
different between the four locations. For color, the L, a* and b* values ranged from 44.18 to 52.52, 0.04 to
2.15 and 10.36 to 14.82, respectively. The flavonoid content of honey samples ranged from 0.28 to 0.42
mg/ml as mg catechin equivalents (CEQ) per ml of honey while phenolic content gives the value from 39.38
to 78.44 mg/L as mg of Gallic acid equivalents (GAE) per L of honey. Antioxidants activity of this honey
gives value from 77.26 to 85.54% which the lowest was Banggol Peradong and the highest was Benting
Lintang. The major component of minerals as sulphur (S), calcium (Ca), magnesium (Mg) and sodium (Na)
ranged from 63.929 to 118.902 mg/L, 12.197 to 29.342 mg/L, 5.816 to 27.364 mg/L and 18.095 to 40.170
mg/L, respectively. It can be concluded that the physichochemical and minerals content of honey by H. itama
is differ between locations due to the variation of plant diversity at respective locations. Data obtained
provide the information on the effect of spatial biodiversity variation on the quality of stingless bee honey in
Malaysia
Listeria monocytogenes contamination in chicken offal at wet market and supermarket
No full textListeria monocytogenes is a foodborne pathogen that cause serious illness in vulnerable individuals such as infant,
pregnant woman, elderly and immunocompromised patient. This study aimed to determine the prevalence of
L. monocytogenes in chicken offal samples between wet market and supermarket. A total of 428 chicken offal
samples (chicken gizzard=154, heart=131, liver=143) from wet markets and supermarkets in Klang Valley,
Malaysia were examined using multiplex polymerase chain reaction (PCR) assay and conventional plating
method. Both PCR assay and plating method are equally reliable in detecting the presence of L. monocytogenes
in chicken offal. The prevalence of Listeria spp. and L. monocytogenes from total samples was 8.9% and 6.5%,
respectively. L. monocytogenes in chicken offal was found gizzard, liver, and heart at 10.4%, 7.0%, and 1.5%,
respectively. L. monocytogenes contamination in samples from supermarkets was significantly higher than those
in wet markets which might due to the pathogen psychrophilic characteristic. It can be concluded that
refrigerated samples have higher prevalence of L. monocytogenes contamination
BAB 14 : Pengurusan Risiko dan Kemalangan di Jabatan Radiologi dalam Mendepani Pandemik COVID-19
No full textScalability analysis of low-power wide area network technology
No full textLow-power wide area network is a new wireless communication technology designed for low-power consumption
together with long-distance communications, and LoRa technology is one of the leading technology solutions. The
long-range connection between end-nodes and gateway is achievable by LoRa devices due to star-based network
topology and modulation techniques used in wireless communication of the technology. One of the main features of
LoRa technology is the ability to scale. Modelling and simulation can interpret the actual network behaviour of LoRa
technology as accurate as possible. This paper aims to investigate the performance of the low-power wide area
network technology focusing on capability of the network to scale. We model the network system based on the
behaviours of the communication between the end-node and gateway. The simulation to study the scalability was
done based on several parameters, such as the number of end-nodes, application time and the number of channels
used by the end-node. The results show that the amount of successfully received data signal at gateway increased as
the application time and channel used increased
