Chronic wounds typically comprise of necrotic tissue and dried secretions, often culminating in the formation of a thick and tough layer of dead skin known as eschar. Removal of eschar is imperative to facilitate wound healing. Conventional approach for eschar removal involves surgical excision and grafting, which can be traumatic and frequently leads to viable tissue damage.
View Article and Find Full Text PDFFlavin reductases play a vital role in catalyzing the reduction of flavin through NADH or NADPH oxidation. The gene encoding flavin reductase from the thermophilic bacterium Geobacillus mahadii Geo-05 (GMHpaC) was cloned, overexpressed in Escherichia coli BL21 (DE3) pLysS, and purified to homogeneity. The purified recombinant GMHpaC (Class II) contains chromogenic cofactors, evidenced by maximal absorbance peaks at 370 nm and 460 nm.
View Article and Find Full Text PDFThis study investigated antioxidant and anti-inflammatory peptides from Edible Bird's Nest (EBN). The prepared EBN peptides were sequentially separated, purified, and successively identified by ultrafiltration, gel filtration and mass spectrometry techniques. Four potential antioxidant and anti-inflammatory peptides were identified as Peptide 1 (LFWSPSVYLK), Peptide 2 (GWPHLEDNYLDW), Peptide 3 (NPPADLHK) and Peptide 4 (GDLAYLDQGHR).
View Article and Find Full Text PDFIn nature, bacteria are ubiquitous and can be categorized as beneficial or harmless to humans, but most bacteria have one thing in common which is their ability to produce biofilm. Biofilm is encased within an extracellular polymeric substance (EPS) which provides resistance against antimicrobial agents. Protease enzymes have the potential to degrade or promote the growth of bacterial biofilms.
View Article and Find Full Text PDFCyanobacteria are the most abundant oxygenic photosynthetic organisms inhabiting various ecosystems on earth. As with all other photosynthetic organisms, cyanobacteria release oxygen as a byproduct during photosynthesis. In fact, some cyanobacterial species are involved in the global nitrogen cycles by fixing atmospheric nitrogen.
View Article and Find Full Text PDFNatural astaxanthin is known to be produced by green microalgae, a potent producer of the most powerful antioxidant. To increase the productivity of astaxanthin in microalgae, random mutagenesis has been extensively used to improve the yield of valuable substances. In the presented work, a newly isolated sp.
View Article and Find Full Text PDFAcinetobacter baumannii is a ubiquitous bacteria that is increasingly becoming a formidable nosocomial pathogen. Due to its clinical relevance, studies on the bacteria's secretory molecules especially extracellular proteases are of interest primarily in relation to the enzyme's role in virulence. Besides, favorable properties that extracellular proteases possess may be exploited for commercial use thus there is a need to investigate extracellular proteases from Acinetobacter baumannii to gain insights into their catalytic properties.
View Article and Find Full Text PDFThe Johor Strait has experienced rapid development of various human activities and served as the main marine aquaculture area for the two countries that bordered the strait. Several fish kill incidents in 2014 and 2015 have been confirmed, attributed to the algal blooms of ichthyotoxic dinoflagellates; however, the cause of fish kill events after 2016 was not clarified and the causative organisms remained unknown. To clarify the potential cause of fish kills along the Johor Strait, a 1-year field investigation was conducted with monthly sampling between May 2018 and April 2019.
View Article and Find Full Text PDFA halophilic bacterium, sp. strain CD6, was isolated from salted fish and its extracellular protease was characterized. Protease production was found to be highest when yeast extract was used as nitrogen source for growth.
View Article and Find Full Text PDFThe D-2-haloacid dehalogenase of D-specific dehalogenase (DehD) from sp. RC1 catalyses the hydrolytic dehalogenation of D-haloalkanoic acids, inverting the substrate-product configuration and thereby forming the corresponding L-hydroxyalkanoic acids. Our investigations were focused on DehD mutants: R134A and Y135A.
View Article and Find Full Text PDFHalogenated compounds are recalcitrant environmental pollutants prevalent in agricultural fields, waste waters and industrial by-products, but they can be degraded by dehalogenase-containing microbes. Notably, 2-haloalkanoic acid dehalogenases are employed to resolve optically active chloropropionates, as exemplified by the d-specific dehalogenase from sp. RCI (DehD), which acts on d-2-chloropropionate but not on its l-enantiomer.
View Article and Find Full Text PDFAstaxanthin, a carotenoid pigment found in several aquatic organisms, is responsible for the red colour of salmon, trout and crustaceans. In this study, astaxanthin production from freshwater microalga Chlorella sorokiniana and marine microalga Tetraselmis sp. was investigated.
View Article and Find Full Text PDFCurrently, there is no three-dimensional structure of D-specific dehalogenase (DehD) in the protein database. We modeled DehD using ab initio technique, performed molecular dynamics (MD) simulation and docking of D-2-chloropropionate (D-2CP), D-2-bromopropionate (D-2BP), monochloroacetate (MCA), monobromoacetate (MBA), 2,2-dichloropropionate (2,2-DCP), d,l-2,3-dichloropropionate (d,l-2,3-DCP), and 3-chloropropionate (3-CP) into the DehD active site. The sequences of DehD and D-2-haloacid dehalogenase (HadD) from Pseudomonas putida AJ1 have 15% sequence similarity.
View Article and Find Full Text PDFThe specificities of glycosyltransferases make them useful for the synthesis of biologically active oligosaccharides, but also restrict their range of products. In substrate engineering, substrate promiscuity is enhanced by attaching removable interactive groups to weak substrates. Thus, the attachment of betap-nitrophenyl converts galactose from a poor into a good substrate of alpha-1,3-galactosyltransferase.
View Article and Find Full Text PDFComplex glycans have important roles in biological recognition processes and considerable pharmaceutical potential. The synthesis of novel glycans can be facilitated by engineering glycosyltransferases to modify their substrate specificities. The choice of sites to modify requires the knowledge of the structures of enzyme-substrate complexes while the complexity of protein structures necessitates the exploration of a large array of multisite mutations.
View Article and Find Full Text PDFalpha-1,3-Galactosyltransferase (alpha3GT) catalyzes the transfer of galactose from UDP-galactose to form an alpha 1-3 link with beta-linked galactosides; it is part of a family of homologous retaining glycosyltransferases that includes the histo-blood group A and B glycosyltransferases, Forssman glycolipid synthase, iGb3 synthase, and some uncharacterized prokaryotic glycosyltransferases. In mammals, the presence or absence of active forms of these enzymes results in antigenic differences between individuals and species that modulate the interplay between the immune system and pathogens. The catalytic mechanism of alpha3GT is controversial, but the structure of an enzyme complex with the donor substrate could illuminate both this and the basis of donor substrate specificity.
View Article and Find Full Text PDFInterferon-gamma-inducible protein (IP-10) belongs to the CXC class of chemokines and plays a significant role in the pathophysiology of various immune and inflammatory responses. It is also a potent angiostatic factor with antifibrotic properties. The biological activities of IP-10 are exerted by interactions with the G-protein-coupled receptor CXCR3 expressed on Th1 lymphocytes.
View Article and Find Full Text PDFAlpha-1,3 galactosyltransferase (alpha3GT) catalyzes the transfer of galactose from UDP-galactose to beta-linked galactosides with retention of its alpha configuration. Although several complexes of alpha3GT with inhibitors and substrates have been reported, no structure has been determined of a complex containing intact UDP-galactose. We describe the structure of a complex containing an inhibitory analogue of UDP-galactose, UDP-2F-galactose, in a complex with the Arg365Lys mutant of alpha3GT.
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