Explore chapters and articles related to this topic
Fungal allergens
Published in Richard F. Lockey, Dennis K. Ledford, Allergens and Allergen Immunotherapy, 2020
Robert E. Esch, Jonathan A. Bernstein, Hari M. Vijay
Asp f 3 has been identified as a major allergen based on immediate skin test reactivity, peripheral blood mononuclear cell proliferation, and strong IgE binding in up to 94% of patients with ABPA. The primary structure reveals sequence homology among identified IgE epitopes of peroxisomal membrane proteins from Candida boidinii [149], Malassezia furfur [150], and Pencillium citrinum [151]. Linear IgE-binding regions were demonstrated using synthetic peptides spanning the entire molecule using sera from patients with ABPA in IgE-ELISA and Western blotting. Conformational determinants were identified at the N-terminal and C-terminal ends using mutant recombinant Asp f 3 proteins deleted off the specific IgE-binding regions. The IgE-binding patterns of the respective mutant Asp f 3 molecules suggested that together the N-terminal residues 1–12 and the C-terminal residues 143–150 were necessary for maintaining the IgE-binding conformational structure [152].
Synthesis of Important Chiral Building Blocks for Pharmaceuticals Using Lactobacillus and Rhodococcus Alcohol Dehydrogenases
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Marion Rauter, Simon Krebs, Gotthard Kunze
FDH from Candida boidinii was the first enzyme being used in industrial processes (Kragl et al., 1996; Bommarius et al., 1994; Bommarius et al., 1998; Bommarius et al., 1995; Shaked and Whitesides, 1980). Formate is oxidized to CO2, which makes the process irreversible and shifts the reaction balance to NADH regeneration. However, for many industrial processes the use of FDH is not feasible, due to the low specific activity of 6 U mg−1 (Slusarczyk et al., 2000) and high production costs as well as its sensitivity against organic solvents (van der Donk and Zhao, 2003). In addition, wild-type FDH reduces only NAD+, but not NADP+. Later in 2008, Andreadeli et al. identified a double-mutant with 2 × 107-fold improvement of overall catalytic efficiency of NADP+ reduction and a more than 900-fold decrease of efficiency with NAD+, so that its application with Lactobacillus ADHs became possible.
Distribution and Biological Functions of Pyruvate Carboxylase in Nature
Published in D. B. Keech, J. C. Wallace, Pyruvate Carboxylase, 2018
As is evident from the data summarized in Table 2, pyruvate carboxylase activity has been found to occur in several other yeasts (viz., Schizosaccharomyces pombe,240Rhodotorula glutinis,710 Hansenula anomala,710 and four species of Candida147,240,508,559) at much the same level as in Saccharomyces cerevisiae. Growth on aspartate- or malate-containing media reduced the pyruvate carboxylase activity of Rhodotorula glutinis710 as it did for Saccharomyces cerevisiae,355,357,619 while inclusion of bicarbonate (50 m M) in the medium increased the activity of the enzyme two- to threefold in Candida boidinii growing on methanol.147 In neither case was the molecular basis of this change in activity reported.
Alcohol quantification: recent insights into amperometric enzyme biosensors
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Vinita Hooda, Vikas Kumar, Anjum Gahlaut, Vikas Hooda
The growing need of developing analytical methods to perform rapid “in situ” analyses of ethanol led to the emergence of miniaturized disposable screen printed electrodes (SPE). The manufacturing of SPEs involves the deposition of multiple successive layers of different ink onto the planar ceramic or plastic supports. The composition of the inks which are used in printing process can be modified by adding different substances like enzymes, complexing agents and metals etc. SPEs present great flexibility for their use in biosensors as transducers because they can be easily modified by using nanostructures, mediators or conducting polymers to improve electron transfer rate. They are easy to prepare as well as suitable for working with micro-volumes. In addition, SPEs show excellent selectivity, reusability and sensitivity. Ramaa et al. studied different alcohol biosensors based on screen-printed carbon electrodes and compared them. They developed single-use alcohol enzyme sensors by utilizing AOX from 3 different yeasts namely Candida boidinii, Hansenula sp. and Pichia pastoris and using 3 different mediators based Screen-printed carbon Electrodes as transducers. The mediators such as Ferrocyanide, Prussian blue and Co-phthalocyanine were incorporated into the ink of the working electrode. The best results were shown by biosensor using Screen-Printed Co-phthalocyanine/Carbon Electrode and enzyme AOX purified from Hansenula sp. It showed a wide linear response of 0.05–1.00 mM and sensitivity of around 1211 nA mM−1 [20]. Boujtita et al. developed a disposable ethanol sensor based on a chemically altered screen-printed carbon electrode coated with AOX for the measurement of ethanol in beer [61]. Then Luo et al. reported a biosensor for detecting serum alcohol concentration. They fabricated the biosensor by cross-linking the enzyme AOX and NAD+ on the screen printed electrode modified with Meldola's Blue (MB) mediator absorbed on Nafion. The biosensor showed satisfactory results for the measurement of serum alcohol [62]. Later, Erhui Hua reported an integrated disposable ethanol biosensor based on the ADH/NAD+/Meldola’s blue (MDB)/graphitized mesoporous carbons (GMCs)/chitosan nanobiocomposite fabricated on a screen printed electrode (SPE). It presented excellent sensitivity of 10.36 nA μM−1 with fast response time of 5 s [33]. Recently in 2016, an ethanol biosensor was developed by Melike et al. by modifying screen printed carbon electrode with gold nanoparticles (AuNPs), polyneutral red (PNR), multiwalled carbon nanotubes (MWCNTs) and ADH enzyme. This biosensor was tested on real alcoholic beverage samples. The sensitivity and limit of detection of the proposed sensor was found to be 0.49 μA mM−1 and 96.1 μM, respectively [63].