Publications by authors named "Le Thien Kim"

, a member of the family Enterobacteriaceae, is a rod-shaped, Gram-negative bacterium, mainly found in the hospital environment and medical tools. It is the leading cause of nosocomial infection, characterized by bloodstream infection, wound site infection, urinary tract infection, and sepsis, mostly in older adults, newborn infants, and immunocompromised patients. This present study demonstrated a novel diagnostic method for detection based on the gold nanozyme activity for the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of HO.

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Tenatoprazole, a newly developed proton pump inhibitor candidate, was developed as an acid inhibitor for gastric acid hypersecretion disorders such as gastric ulcer and reflux esophagitis. It is known that tenatoprazole is metabolized to three major metabolites of 5'-hydroxy tenatoprazole, tenatoprazole sulfide, and tenatoprazole sulfone in human liver, primarily catalyzed by CYPs 2C19 and 3A4. While CYP2C19 prefers the hydroxylation of tenatoprazole at C-5' position, CYP3A4 is mainly involved in sulfoxidation reaction to make tenatoprazole sulfone.

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Article Synopsis
  • One-carbon (C1) chemicals, like methanol and methane, can be used as sustainable resources for making everyday products and pharmaceuticals.
  • Methanol is considered a key renewable feedstock because it can be produced from various bioresources through a process called syngas.
  • The enzyme methanol dehydrogenase (Mdh) plays a crucial role in converting methanol to formaldehyde, and this review discusses its properties and engineering to enhance synthetic methylotrophic bacteria for better production.
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  • The study focuses on the biodegradation of polystyrene (PS), a major plastic waste that is notoriously hard to break down, using specific bacterial cultures found in soil.
  • Two bacterial strains, Pseudomonas lini JNU01 and Acinetobacter johnsonii JNU01, were identified as effective in growing and degrading PS when cultivated in a nutrient medium with PS as the sole carbon source.
  • Various analytical techniques, including spectroscopy and microscopy, confirmed the biodegradation process and identified the alkane-1-monooxygenase enzyme (AlkB) in A. johnsonii JNU01 as key in facilitating PS breakdown, highlighting the potential of these microbes in managing
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Article Synopsis
  • The cover features a joint research group from KAIST and CNU, led by Prof. Chan Beum Park and Prof. Chul-Ho Yun.
  • The study highlights how flavin mononucleotide, a natural photosensitizer, combined with visible light can create an eco-friendly and cost-effective method for P450-catalyzed reactions.
  • More details about the research can be found at the provided DOI: 10.1002/cssc.202100944.
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Plastic contamination currently threatens a wide variety of ecosystems and presents damaging repercussions and negative consequences for many wildlife species. Sustainable plastic waste management is an important approach to environmental protection and a necessity in the current life cycle of plastics in nature. Plastic biodegradation by microorganisms is a notable possible solution.

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Article Synopsis
  • Photobiocatalysis is an eco-friendly method that utilizes solar energy to facilitate redox enzymatic reactions without the need for expensive cofactors.
  • A new system was developed using natural flavins as a photosensitizer to drive human cytochrome P450 (CYP) reactions with visible light, showcasing its effectiveness both in vitro and in whole-cell systems.
  • The study found that various factors like substrate type and the presence of catalase influence the photobiocatalytic activity of CYP2E1, indicating broad potential for applying this solar-powered method to other human CYPs.
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Although data on the prevalence of anticholinergic misuse is scarce, it has been reported among psychiatric patients. Anticholinergic drugs can act as potent indirect dopamine agonists in the limbic system, a mechanism that has been hypothesized to explain their misuse potential among patients. In psychiatric practice settings, the use of typical antipsychotics in conjunction with anticholinergics is common, with the latter mainly used to manage extrapyramidal side effects of the former.

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Methanol dehydrogenase (Mdh), is a crucial enzyme for utilizing methane and methanol as carbon and energy sources in methylotrophy and synthetic methylotrophy. Engineering of Mdh, especially NAD-dependent Mdh, has thus been actively investigated to enhance methanol conversion. However, its poor catalytic activity and low methanol affinity limit its wider application.

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Phloretin, the major polyphenol compound in apples and apple products, is interesting because it shows beneficial effects on human health. It is mainly found as a form of glucoside, phlorizin. However, the metabolic pathway of phloretin in humans has not been reported.

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In this study, we investigated an efficient enzymatic strategy for producing potentially valuable phloretin metabolites from phlorizin, a glucoside of phloretin that is rich in apple pomace. Almond β-glucosidase efficiently removed phlorizin's glucose moiety to produce phloretin. CYP102A1 engineered by site-directed mutagenesis, domain swapping, and random mutagenesis catalyzed the highly regioselective C-hydroxylation of phloretin into 3-OH phloretin with high conversion yields.

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Article Synopsis
  • - The study investigates how the absence of ovarian hormones affects muscarinic receptor function and prepulse inhibition (PPI), a measure linked to schizophrenia, using ovariectomized and sham-operated female rats.
  • - PPI tests showed no significant differences between the two groups after treatments with saline or scopolamine, indicating that ovarian hormone removal did not affect sensorimotor gating.
  • - Additionally, analysis of muscarinic receptor density in various brain regions (like the amygdala and hippocampus) revealed no group differences, suggesting that ovarian hormones do not play a crucial role in the cholinergic muscarinic receptor system regarding PPI.
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Twelve new terpenoids (-) were isolated from the stems of , an anti-inflammatory medicinal plant traditionally used in Vietnam. Most of them (-) possess a sesquiterpenoid backbone (e.g.

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The number of undocumented immigrants (UIs) varies worldwide, and most reside in the United States. With more than 12 million UIs in the United States, addressing the health care needs of this population presents unique challenges and opportunities. Most UIs are uninsured and rely on the safety-net health system for their care.

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Objectives: To find the catalytic activities of CYP191A1 from Mycobacterium smegmatis, in which functions of most P450s are unknown, by using a set of reductase systems, peroxides, and various substrates including fatty acids and human drugs.

Results: CYP191A1 was functionally expressed in Escherichia coli and purified. Its catalytic activities were examined with fatty acids, chromogenic and fluorogenic substrates, and several human P450 substrates, in the presence of six different types of electron transfer systems, such as rat NADPH-P450 reductase, Candida NADPH-P450 reductase, ferredoxin/ferredoxin reductase, putidaredoxin/putidaredoxin reductase, and peroxides (HO and t-butyl hydroperoxide).

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The number of undocumented immigrants (UIs) varies worldwide, and most reside in the United States. With more than 12 million UIs in the United States, addressing the health care needs of this population presents unique challenges and opportunities. Most UIs are uninsured and rely on the safety-net health system for their care.

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Enzymatic conversion of natural glycosides to their corresponding hydroxylated products using cytochromes P450 has significant advantages over synthetic chemistry and even enzyme-catalyzed glycosylation of chemicals. At present, the basic strategy for making glycosides of stilbenoid compounds is to use the glycosylation activity of enzymes, such as glycosyltransferases. Here, an efficient synthesis of a valuable (E)-astringin, a piceatannol glucoside, was developed using CYP102A1 via the highly regioselective C-3' hydroxylation of polydatin, a resveratrol glucoside.

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produces clinically useful drugs such as avermectins and oligomycins. Its genome contains approximately 33 cytochrome P450 genes and they seem to play important roles in the biosynthesis of many secondary metabolites. The gene from encodes CYP158A3.

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Objectives: To find a simple enzymatic strategy for the efficient synthesis of the expensive 5'-hydroxyomeprazole sulfide, a recently identified minor human metabolite, from omeprazole sulfide, which is an inexpensive substrate.

Results: The practical synthetic strategy for the 5'-OH omeprazole sulfide was accomplished with a set of highly active CYP102A1 mutants, which were obtained by blue colony screening from CYP102A1 libraries with a high conversion yield. The mutant and even the wild-type enzyme of CYP102A1 catalyzed the high regioselective (98 %) C-H hydroxylation of omeprazole sulfide to 5'-OH omeprazole sulfide with a high conversion yield (85-90 %).

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Members of the SoxB transcription factor family play critical roles in the regulation of neurogenesis. The SoxB1 proteins are required for the induction and maintenance of a proliferating neural progenitor population in numerous vertebrates, however the role of the SoxB2 protein, Sox21, is less clear due to conflicting results. To clarify the role of Sox21 in neurogenesis, we examined its function in the Xenopus neural plate.

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Terminases are enzymes that are required for the insertion of a single viral genome into the interior of a viral procapsid by a process referred to as 'encapsulation or packaging'. Many double-stranded DNA viruses such as bacteriophages T3, T4, T7, λ and SPP1, as well as herpes viruses, utilize terminase enzymes for this purpose. All the terminase enzymes described to date require two subunits, a small subunit referred to as TerS and a large subunit referred to as TerL, for in vivo activity.

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