• Mass Spectrometry Letters
• /
• v.5 no.1
• /
• pp.1-11
• /
• 2014

Lipids play important roles in biological systems; they store energy, play a structural role in the cell membrane, and are involved in cell growth, signal transduction, and apoptosis. Phospholipids (PLs) in particular have received attention in the medical and lipidomics research fields because of their involvement in human diseases such as diabetes, obesity, atherosclerosis, and many cancers associated with lipid metabolic disorders. Here I review experimental strategies for PL analysis based on nanoflow liquid chromatography-electrospray ionization-tandem mass spectrometry (nLC-ESI-MSn). In particular, discussed are lipid extraction methods, nanoflow LC separation of PLs, effect of ionization modifiers on the ESI of PLs, influence of chain lengths and unsaturation degree of acyl chains of PLs on MS intensity, structural determination of the molecular structure of PLs and their oxidized products, and quantitative profiling of PLs from biological samples such as tissue, urine, and plasma in relation to cancer and coronary artery disease.

• 한국유가공학회:학술대회논문집
• /
• 2007.09a
• /
• pp.31-37
• /
• 2007

An understanding functional properties and molecular interactions of milk proteins was critical to improve qualities of fermented dairy products including yogurts and cheeses. Extensive rearrangements of casein particles were important factors to enhance whey separation in yogurt gel network. The use of high hydrostatic pressure treated whey protein as an ingredient of low fat processed cheese food resulted in the production of low fat processed cheese food with acceptable firmness and enhanced meltabilities. Milk protein-based nano particles produced by self-association of proteins could be better nutrient delivery vehicle than micro particle since particle size reduction in nano particles could lead to increased residence time and surface area available in GI tract.

• KSBB Journal
• /
• v.20 no.3
• /
• pp.133-141
• /
• 2005

This review presents the preparation, transport mechanism and application of molecularly imprinted membranes (MIM). Molecular imprinting has now been established as a technique which allows the creation of tailor-made binding sites for many classes of compounds. MIM have some advantages; a high capacity due to a large surface area, faster transport of substrate molecules and faster equilibrium of binding cavities compared to molecularly imprinted particles. MIM were prepared by covalent and non-covalent chemical bonding systems, by interactions between functional monomer and template. MIM can be prepared by in-situ polymerization, wet phase inversion, dry phase inversion, and surface imprinting method. MIM can continuously separate mixtures based on facilitated or retarded diffusion of the template. MIM can change their permeability in the presence of templates. MIM have a potential to be used to separate chiral compounds and materials with similar structures. However the application of MIM by the chemical industries is still in its infancy stages.

• Proceedings of the Membrane Society of Korea Conference
• /
• 2004.05b
• /
• pp.188-191
• /
• 2004

Carbon molecular sieve (CMS) membranes have superior gas permeation and separation performance compared with polymeric membranes$^{1.3}$ . Up to now, CMS membranes mostly have been mostly focused on the kinds of precursor and pyrolysis condition (pyrolysis temperature, heating rate, pyrolysis atmosphere).(omitted)

• Korean Membrane Journal
• /
• v.1 no.1
• /
• pp.50-58
• /
• 1999

Symmetric asymmetric and composite perfluoropolymer membranes made with HYFLON AD have been prepared and evaluated. Porous and non porous symmetric membranes have been prepared by solvent evaporation with various processing conditions. Non-contact atomic force microscopy (AFM) was used to investigate the membrane morphology in air. Analysis of the images gave quantitative imformation on the surface pore strcture in particular on the pore size distributin. Possible useful uses of porous membranes are envisaged in the field of gas-liquid separations such as membrane contactors (MSc) Molecular Dynamics(MD) simulations structure of HYFLON AD 60X copolymer supporting these results are also reported. Amorphous perfluoropolymer membranes appears to be ideal other than in MCs when separation processes have to be performed in hostile environments i.e. high temperatures and aggressive non-aqueous media such as chemicals and solvents. In these cases HYFLON AD mem-branes can exploit the outstanding resistance of perfluoropolymers.

• BMB Reports
• /
• v.38 no.3
• /
• pp.370-372
• /
• 2005

A cross-linked leucaena (Leucaena leucocephala) seed gum (CLLSG) matrix was prepared for the isolation of galactose-specific lectins by affinity chromatography. The matrix was evaluated for affinity with a known galactose-specific lectin from the seeds of snake gourd (Trichosanthes anguina). The matrix preparation was simple and inexpensive when compared to commercial galactose-specific matrices (i.e. about 1.5 US$/100 ml of matrix). The current method is also useful for the demonstration of the affinity chromatography technique in laboratories. Since leucaena seeds are abundant and inexpensive, and the matrix preparation is easy, CLLSG appears to be a promising tool for the separation of galactose-specific lectins.

• BMB Reports
• /
• v.37 no.4
• /
• pp.387-393
• /
• 2004

The L-asparaginase (E. C. 3. 5. 1. 1) enzyme was purified to homogeneity from Pseudomonas aeruginosa 50071 cells that were grown on solid-state fermentation. Different purification steps (including ammonium sulfate fractionation followed by separation on Sephadex G-100 gel filtration and CM-Sephadex C50) were applied to the crude culture filtrate to obtain a pure enzyme preparation. The enzyme was purified 106-fold and showed a final specific activity of 1900 IU/mg with a 43% yield. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of the purified enzyme revealed it was one peptide chain with $M_r$ of 160 kDa. A Lineweaver-Burk analysis showed a $K_m$ value of 0.147 mM and $V_{max}$ of 35.7 IU. The enzyme showed maximum activity at pH 9 when incubated at $37^{\circ}C$ for 30 min. The amino acid composition of the purified enzyme was also determined.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.6
• /
• pp.503-509
• /
• 2006

Molecularly imprinted polymeric microbeads (MIPMs) were prepared by the suspension and modified suspension polymerization methods using D-phenylalanine as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, toluene as the porogen, polyvinyl alcohol as the stabilizer, and sodium dodecyl sulfate as the surfactant. The addition of a surfactant to the conventional suspension polymerization mixture decreased the mean particle size of the MIPMs and increased the adsorption selectivity. For the modified suspension polymerization method, the mean particle size of the MIPMs was smaller than the particle size of MIPMs prepared via conventional suspension polymerization. Moreover, the adsorption selectivity improved considerably compared to the adsorption selectivities of MIPs reported previously.

• Animal Systematics, Evolution and Diversity
• /
• v.36 no.3
• /
• pp.268-273
• /
• 2020

A spionid polychaete, Boccardiella hamata (Webster, 1879) has been found from mud in crevices between the shells of oysters and adherent substrates in South Korea. The sequences of mitochondrial DNA (mtDNA) cytochrome c oxidase subunit 1 (CO1), 16S ribosomal DNA (16S), and the nuclear 18S ribosomal DNA (18S) from Korean individuals of Boccardiella hamata were determined in the present study. The molecular analysis based on the 18S rRNA gene sequences showed clear separation among the spionid polychaete species, and the sequences of Korean and Japanese individuals are completely identical. The morphological diagnosis and photographs of B. hamata are also provided.

• ALGAE
• /
• v.36 no.2
• /
• pp.111-121
• /
• 2021

Two cyanobacterial morphotypes isolated from Signy Island, South Orkney Islands, maritime Antarctica were characterised using a polyphasic approach combining morphological, cytological and molecular analyses. These analyses showed that the strains grouped with members of the genus Wilmottia. This genus currently includes three species, W. murrayi, W. stricta, and W. koreana. Both morphotypes analysed in this study were placed within the clade of W. murrayi. This clade showed a well-supported separation from Antarctic and New Zealand strains, as well as strains from other regions. W. murrayi was first described from Antarctica and is now known from several Antarctic regions. Confirmation of the occurrence of W. murrayi at Signy Island significantly extends its known distribution in Antarctica. In addition, a new combination, W. arthurensis, is suggested for Phormidium arthurensis.