Youngae Lee
Ulsan National Institute of Science and Technology · 数学
研究室紹介
Professor Youngae Lee's research lab specializes in the photophysical and structural characterization of biomolecular interactions, particularly focusing on the binding modes of synthetic and metallo-porphyrins, ruthenium complexes, and fluorescent probes with nucleic acids such as duplex DNA, G-quadruplexes, and triplexes. The lab employs advanced spectroscopic techniques—including circular dichroism (CD), linear dichroism (LD), and fluorescence spectroscopy—under both physiological and molecular crowding conditions to elucidate the dynamics and selectivity of ligand–nucleic acid interactions. A key research direction involves understanding how molecular crowding, mimicked by poly(ethylene glycol), influences binding affinity and mode, with implications for drug design and nucleic acid-based sensing.
Research Overview
Research Output Trend
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Selected Papers
15Induced CD spectra of meso-tetrakis(N-methylpyridium-4-yl)porphyrin (TMPyP) complexed with d(A)12.d(T)12, d(G)12.d(C)12 duplex and d(A)12.[d(T)12]2, d(G)12.d(C)12.d(C)12+ triplex in the Soret band were compared in this study. When TMPyP is complexed with the duplex, a monomeric CD spectrum at a low [TMPyP]/[oligomer] ratio was apparent, while at a high mixing ratio, the excitonic CD was dominant. In contrast, when TMPyP was complexed with the triplex, the excitonic CD disappears at a relatively
Meso-tetrakis(N-methyl pyridinium-4-yl)porphyrin (TMPyP) intercalates between the base-pairs of DNA at a low [TMPyP]/[DNA base] ratio in aqueous solutions and molecular crowding conditions, which is induced by the addition of Poly(ethylene glycol) (PEG). Studied DNA-binding drugs, including TMPyP, 9-aminoacridine, ethidium bromide, and DAPI (4',6-diamidino-2-phenylindole) showed similar binding properties in the presence or absence of PEG molecules which is examined by circular and linear dichro
The binding modes of various cationic porphyrins to DNA in an aqueous solution and under the molecular crowding condition induced by poly(ethylene glycol) (PEG) were compared by normal absorption, circular dichroism (CD), and linear dichroism (LD) spectroscopy techniques. Large negative CD and LD signals in the Soret absorption regions of the meta- and para-TMPyP [meso-tetrakis (n-N-methylpyridiniumyl) porphyrin (meta, n = 3) and (para, n = 4)] were apparent in the aqueous solution, indicating a
The pioneering work of Brezis-Merle [7 Brezis, H., Merle, F. (1991). Uniform estimates and blow-up behavior for solutions of −Δu = V(x)eu in two dimensions. Commun. Partial Differential Equation 16:1223–1254.[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]], Li-Shafrir [27 Li, Y.Y., Shafrir, I. (1994). Blow-up analysis for solutions of −Δu = V(x)eu in dimension two. Indiana Univ. Math. J. 43:1255–1270.[Crossref], [Web of Science ®] , [Google Scholar]], Li [26 Li, Y.Y. (1999). Har
The interaction of Δ- and Λ-[Ru(phen)<sub>2</sub>DPPZ]<sup>2+</sup> (DPPZ = dipyrido[3,2-a:2', 3'-c]phenazine, phen = phenanthroline) with a G-quadruplex formed from 5'-G<sub>2</sub>T<sub>2</sub>G<sub>2</sub>TGTG<sub>2</sub>T<sub>2</sub>G<sub>2-3</sub>'(15-mer) was investigated. The well-known enhancement of luminescence intensity (the 'light-switch' effect) was observed for the [Ru(phen)<sub>2</sub>DPPZ]<sup>2+</sup> complexes upon formation of an adduct with the G-quadruplex. The emission inte
The fluorescence intensity of a single-stranded oligonucleotide containing a fluorene-labeled deoxyuridine <TEX>$(U^{Fl})$</TEX> unit increases by only 1.5-fold upon formation of its perfectly matched duplex. To increase the fluorescence signal during hybridization, we positioned a quencher strand containing a deoxyguanine (dG) nucleobase, functioning as an internal quencher, opposite to the <TEX>$U^{Fl}$</TEX> unit to reduce the intrinsic fluorescence upon hybridization with a probe. From an in
When meso-tetrakis(3-N-methylpyridiniumyl)porphyrin (m-TMPyP) formed a complex with poly[d(A-T)(2)], an intense bisignate excitonic CD in the Soret absorption region was observed. The excitonic CD of the m-TMPyP-poly[d(A-T)(2)] complex is unique in that no other combination of the related porphyrin, namely, meso-tetrakis(n-N-methylpyridiniumyl)porphyrin (where n = 2, 4), and polynucleotide including calf thymus DNA, poly[d(G-C)(2)], poly[d(I-C)(2)], and poly(dA).poly(dT), exhibits a comparable C
Oxidatively generated guanine radicals in DNA can undergo various nucleophilic reactions including the formation of C8-guanine cross-links with adjacent or nearby N3-thymines in DNA in the presence of O2. These G[8-3]T lesions have been identified in the DNA of human cells exposed to oxidative stress, and are most likely genotoxic if not removed by cellular defence mechanisms. The abilities of several representative polymerases to bypass the G[8-3]T lesions in two different sequence contexts, G*
We consider a nonlinear elliptic system arising in the study of the SU(3) Chern-Simons model on a two-dimensional flat torus Ω. Solutions of this SU(3) Chern Simons system could be classified as topological, mixed-type, and non-topological solutions. In this paper, we succeed to construct bubbling mixed type solutions. This is the first result for such example in the literature. The analysis for the existence of such solution provides some important insights for us to develop the asymptotic anal