Jung-Kul Lee

Enzymes found in nature have been exploited in industry due to their inherent catalytic properties in complex chemical processes under mild experimental and environmental conditions. The desired industrial goal is often difficult to achieve using the native form of the enzyme. Recent developments in protein engineering have revolutionized the development of commercially available enzymes into better industrial catalysts. Protein engineering aims at modifying the sequence of a protein, and hence

A novel one-dimensional nanohybrid comprised of conductive graphitic carbon (GC)-coated hollow FeSe2 nanospheres decorating reduced graphene oxide (rGO) nanofiber (hollow nanosphere FeSe2@GC-rGO) was designed as an efficient anode material for sodium ion batteries and synthesized by introducing the nanoscale Kirkendall effect into the electrospinning method. The electrospun nanofibers transformed into hollow nanosphere FeSe2@GC-rGO hybrid nanofibers through a Fe@GC-rGO intermediate. The discharg

Multiple-shelled Fe2O3 yolk-shell particles were synthesized using the spray drying method and intended as a suitable support for the immobilization of commercial enzymes such as glucose oxidase (GOx), horseradish peroxidase (HRP), and laccase as model enzymes. Yolk-shell particles have an average diameter of 1-3 μm with pore diameters in the range of 16 to 28 nm. The maximum immobilization of GOx, HRP, and laccase resulted in the enzyme loading of 292, 307 and 398 mg per g of support, respectiv

Xylose reductase (XR) is a key enzyme in D-xylose metabolism, catalyzing the reduction of D-xylose to xylitol. An NADH-preferring XR was purified to homogeneity from Candida parapsilosis KFCC-10875, and the xyl1 gene encoding a 324-amino-acid polypeptide with a molecular mass of 36,629 Da was subsequently isolated using internal amino acid sequences and 5' and 3' rapid amplification of cDNA ends. The C. parapsilosis XR showed high catalytic efficiency (kcat/Km = 1.46 s(-1) mM(-1)) for D-xylose a

Bacteria that cause infectious diseases adopt biofilms as one of their most prevalent lifestyles. Biofilms enable bacteria to tolerate environmental stress and evade antibacterial agents. This bacterial defense mechanism has rendered the use of antibiotics ineffective for the treatment of infectious diseases. However, many highly drug-resistant microbes have rapidly emerged owing to such treatments. Different signaling mechanisms regulate bacterial biofilm formation, including cyclic dinucleotid

Multienzymatic cascade reactions have garnered the attention of many researchers as an approach for converting CO2 into methanol. The cascade reaction used in this study includes the following enzymes: a formate dehydrogenase (ClFDH), a formaldehyde dehydrogenase (BmFaldDH), and an alcohol dehydrogenase (YADH) from Clostridium ljungdahlii, Burkholderia multivorans, and Saccharomyces cerevisiae, respectively. Because this cascade reaction requires NADH as a cofactor, phosphite dehydrogenase (PTDH

Unique-structured composite microspheres of carbon and MoTe₂ were prepared by a two-step process. Precursor C-MoO_x composite microspheres were prepared by spray pyrolysis, and then the precursor was transformed into C-MoTe₂ composite microspheres by a tellurization process. C-MoTe₂ composites with a uniform distribution of MoTe₂ nanocrystals (C/MoTe₂) and core-shell-structured C-MoTe₂ composites (C@MoTe₂) wer