is the major pathogen of pseudomembranous colitis, and novel antimicrobial agents are sought after for its treatment. Phage-derived endolysins with species-specific lytic activity have potential as novel antimicrobial agents. We surveyed the genome of strain 630 and identified an endolysin gene, Ecd09610, which has an uncharacterized domain at the N-terminus and two catalytic domains that are homologous to glucosaminidase and endopeptidase at the C-terminus.
View Article and Find Full Text PDFBull Tokyo Dent Coll
March 2021
Candida albicans is the primary candidiasis-causing fungal pathogen in humans, and one of its most important virulence factors is the ability to form biofilms. Moreover, these biofilms are often resistant to antifungal agents, so there is a need to develop alternative elimination strategies and therapeutic agents for such infections. The antifungal activity of resveratrol, a phytoalexin polyphenolic compound, impairs the morphological transition of C.
View Article and Find Full Text PDFThe presence of high levels of free fatty acids (FFA) in oil is a barrier to one-step biodiesel production. Undesirable soaps are formed during conventional chemical methods, and enzyme deactivation occurs when enzymatic methods are used. This work investigates an efficient technique to simultaneously convert a mixture of free fatty acids and triglycerides (TAG).
View Article and Find Full Text PDFThe presence of phospholipid has been a challenge in liquid enzymatic biodiesel production. Among six lipases that were screened, lipase AY had the highest hydrolysis activity and a competitive transesterification activity. However, it yielded only 21.
View Article and Find Full Text PDFNeuropilin-1 (NRP1) has been identified as a VEGF-A receptor. DJM-1, a human skin cancer cell line, expresses endogenous VEGF-A and NRP1. In the present study, the RNA interference of VEGF-A or NRP1 suppressed DJM-1 cell proliferation.
View Article and Find Full Text PDFAn engineering approach was applied to an efficient biodiesel production from waste cooking oil. In this work, an enzymatic packed-bed reactor (PBR) was integrated with a glycerol-separating system and used successfully for methanolysis, yielding a methyl ester content of 94.3% and glycerol removal of 99.
View Article and Find Full Text PDFWater activity (a(w)) is a crucial parameter affecting enzymatic synthetic reactions in organic media. In this paper, we report on the a(w) dependence of surface-displayed lipases, genetically immobilized on yeast cells via fusion with cell wall proteins. When Saccharomyces cerevisiae displaying Rhizopus oryzae lipase was used for esterification in n-hexane, equilibrating the dried cells with water prior to the reaction markedly increased the reaction rate.
View Article and Find Full Text PDFA process model for efficient glycerol separation during methanolysis in an enzymatic packed-bed reactor (PBR) was developed. A theoretical glycerol removal efficiency from the reaction mixture containing over 30% methyl esters was achieved at a high flow rate of 540 ml/h. To facilitate a stable operation of the PBR system, a batch reaction prior to continuous methanolysis was conducted using oils with different acid values and immobilized lipases pretreated with methyl esters.
View Article and Find Full Text PDFThe enzymatic process presents an advantage of producing specified phospholipids that rarely exist in nature. In this study, we investigated the regiospecific modification of phosphatidylcholine (PC) in the sn-1 position using immobilized Rhizopus oryzae. In a reaction mixture containing egg yolk PC and exogenous lauric acid (LA) in n-hexane, lipase-producing R.
View Article and Find Full Text PDFThe cell surface engineering system, in which functional proteins are genetically displayed on microbial cell surfaces, has recently become a powerful tool for applied biotechnology. Here, we report on the surfactant modification of surface-displayed lipase to improve its performance for enzymatic synthesis reactions. The lipase activities of the surfactant-modified yeast displaying Rhizopus oryzae lipase (ROL) were evaluated in both aqueous and nonaqueous systems.
View Article and Find Full Text PDFAdipocyte lines are a useful tool for adipocyte research. Recently, a new preadipocyte line designated AP-18 was established from subcutaneous tissue of the C3H/He mouse. In this study, we further characterized AP-18 cells.
View Article and Find Full Text PDFIn this paper, we provide the first report of utilizing recombinant fungal whole cells in enzymatic biodiesel production. Aspergillus oryzae, transformed with a heterologous lipase-encoding gene from Fusarium heterosporum, produced fully processed and active forms of recombinant F. heterosporum lipase (FHL).
View Article and Find Full Text PDFSphingomyelinase (SMase) from Bacillus cereus has been known to be activated by Mg2+, Mn2+, and Co2+, but strongly inhibited by Zn2+. In the present study, we investigated the effects of several kinds of metal ions on the catalytic activity of B. cereus SMase, and found that the activity was inhibited by Zn2+ at its higher concentrations or at higher pH values, but unexpectedly activated at lower Zn2+ concentrations or at lower pH values.
View Article and Find Full Text PDFWe developed a convenient chromogenic assay method for the activity of sphingomyelinase (SMase) from Bacillus cereus. SMase reaction was quenched by Zn(2+), and the released phosphocholine was converted into a choline by the action of alkaline phosphatase. After that, the choline was converted into a chromogenic dye by the actions of choline oxidase and peroxidase in the presence of EDTA to trap the added Zn(2+) which could interfere with the choline oxidase/peroxidase reactions.
View Article and Find Full Text PDFThe proton-pumping H+,K+-adenosinetriphosphatase (H,K-ATPase), responsible for acid secretion by the gastric parietal cell, faces a harshly acidic environment, with some pepsin from neighboring chief cells, at its luminal surface. Its large catalytic alpha-subunit is mostly oriented cytoplasmically. The smaller beta-subunit (HKbeta), is mainly extracellular, with one transmembrane domain and a small cytoplasmic domain.
View Article and Find Full Text PDF2-Methyl-8-(phenylmethoxy)imidazo[1,2-a]pyridine-3-acetonitrile (SCH 28080) is a reversible inhibitor specific for the gastric proton pump. The inhibition pattern is competitive with K(+). Here we studied the binding sites of this inhibitor on the putative three-dimensional structure of the gastric proton pump alpha-subunit that was constructed by homology modeling based on the structure of sarcoplasmic reticulum Ca(2+) pump.
View Article and Find Full Text PDFMCS4 RNA is one of the small stable RNAs found in Mycoplasma capricolum subsp. capricolum type strain California kid. This RNA has a sequence similarity to that of eukaryotic U6 snRNA.
View Article and Find Full Text PDFThe gastric proton pump, H(+),K(+)-ATPase, consists of the catalytic alpha-subunit and the noncatalytic beta-subunit. These subunits are assembled in the endoplasmic reticulum (ER) and leave the ER to reach to the cell surface as a functional holoenzyme. We studied the quantity control mechanism of the H(+),K(+)-ATPase in the ER by using a heterologous expression system in human embryonic kidney 293 cells.
View Article and Find Full Text PDFA major obstacle in the treatment of esophageal carcinoma is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Copper-transporting P-type adenosine triphosphatase (ATP7B) has been reported to be associated with cisplatin resistance in vitro. However, the clinical significance of this transporter has not previously been addressed.
View Article and Find Full Text PDFStable cell lines expressing the gastric proton pump alpha- and/or beta-subunits were constructed. The cell line co-expressing the alpha- and beta-subunits showed inward Rb(+) transport, which was activated by Rb(+) in a concentration-dependent manner. In the alpha+beta-expressing cell line, rapid recovery of intracellular pH was also observed after acid load, indicating that this cell line transported protons outward.
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