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Mutant Recombinant Hemoglobin (α96Val→Tyr) Exhibits Low Oxygen Affinity and High Cooperativity
Kim, Hyun-Won,Choi, Jong-Whan,Yeh, Byung-Il,Han, Dong-Pyou,Lee, Hyean-Woo,Sohn, Joon Hyung,Jung, Seunho The Korea Science and Technology Center 1998 BMB Reports Vol.31 No.6
To investigate conformational information of a low oxygen affinity recombinant hemoglobin (rHb) containing 96Val->Trp mutation at the α96 position, we have produced rHb (α96vAL->Phe) and rHb (α96vAL->Tyr), using the Escherichia coli expression system and site-directed mutagenesis. The oxygen affinity of rHb (α96Val->Phe) is similar to that of human normal adult hemoglobin (Hb A). However, the oxygen affinity of rHb (α96Val->Tyr) showed much lower oxygen affinity than Hb A which is similar to that of rHb (α96Val->Trp), providing an opportunity as a potential candidate for a hemoglobin-based blood substitute. Both rHb (α96Val->Phe) and rHb (α96Val->Tyr) showed high cooperativity in oxygen binding. ¹H-NMR spectroscopy shows that both rHb (α96Val->Phe) and rHb (α96Val->Tyr) have very similar tertiary structure around the heme pockets and quaternary structure in the α₁β₁subunit interface compared to Hb A. The low oxygen affinity of rHb (α96Val->Tyr) has been suggested to be due to a hydrogen bond caused by an extra hydroxyl group and not present in rHb (α96Val->Phe). However, investigation of the carbonmonoxy form of rHb (α96Val->Phe) and (α96Val->Tyr) in the presence of inositol hexaphosphate at low temperature suggests that low oxygen affinity of (α96Val->Tyr) may arise from a mechanism different to that of rHb (α96Val->Trp).
Seunho Jung,Jonghyun Lee,Kum Won Cho,Suntae Hwang,Karpjoo Jeong,Youngjin Choi 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.8
A computational study based on molecular dynamics (MD) simulations was performed in order to explain the difference in aqueous solubilities of two flavonoid/-cyclodextrin (-CD) complexes, hesperetin/-CD and naringenin/-CD. The aqueous solubility of each flavonoid/-CD complex could be characterized by complex-water interaction not by flavonoid-CD interaction. The radial distribution of water around each inclusion complex elucidated the difference of an experimentally observed solubility of each flavonoid/-CD complex. The analyzed results suggested that a bulky hydrophobic moiety (-OCH3) of B-ring of hesperetin nearby primary rim of -CD was responsible for lower aqueous solubility of the hesperetin/-CD complex.
메리필드(Merrifield RB.)와 파우너(Powner M.)의 펩타이드 화학합성연구에 대한 현대 과학적 발견들이 시사하는 펩타이드 및 단백질의 비생물속생설 비판
정선호(Seunho Jung) 한국창조과학회 2021 Origin Research Journal Vol.1 No.1
1861년 루이 파스퇴르 (Louis Pasteur)의 백조목 플라스크 실험은 생물의 기원에 대한 자연발생 이론을 반박하고 생물은 생물에서만 그 기원을 설명 할 수 있다는 생물속생설 (biogenesis)을 제안했다. 그후 러시아 생화학자인 오파린 (Alexander Ivanovich Oparin)은 1924년에 원시 지구 생명체의 기원에 대한 화학진화가설을 제안하게 되었다. 이 제안은 1952년에 유레이와 밀러(Urey & Miller)의 실험결과에 기반한 프리바이오틱 화학(prebiotic chemistry)연구를 통해서 보다 다양한 생물의 기원에 대한 실험결과들을 이끌어 낼 수 있었다. 본 소고에서는 최근에 메리필드(Merrifield B.)와 파우너(Powner M.)가 Science 지와 Nature 지등에 각각 발표한 펩타이드의 화학합성 메커니즘과 관련된 연구결과와 과학적 발견들을 고찰하고 해석하였다. 그들의 연구결과들은 펩타이드와 단백질의 기원이 생물의 비생물속생설(abiogenesis)에 근거한 비생체내발생을 의미하는 자연발생이론으로는 설명이 불가능하여, 아직까지도 펩타이드와 단백질의 기원은 파스퇴르의 생물속생설(biogenesis) 이론에 따른 생체내발생을 통해서만 설명이 유효함을 시사하고 있음을 나타낸다. In 1861, Louis Pasteur"s swan-neck flask experiment refuted the spontaneous theory of the origin of life and proposed the theory of biogenesis, which states that living things (life) can only explain their origins. Then, in 1924, Russian biochemist Alexander Ivanovich Oparin proposed the chemical evolutionary hypothesis on the origin of life under the primitive Earth. This proposal could lead to more diverse research results on prebiotic chemistry through the experiments of Urey and Miller in 1952. Here, we provide insight and interpretation of research results and scientific findings related to the chemical synthetic mechanism of peptides recently published by Merrifield RB. and Powner M. in Science and Nature journals. Their research results suggested that the origin of peptides and proteins cannot be explained by abiogenesis, the theory of spontaneous generation of organisms, and that the validity of the Pasteur"s theory of biogenesis still holds true.
Kwon, Nak-Jung,Park, Hee-Soo,Jung, Seunho,Kim, Sun Chang,Yu, Jae-Hyuk American Society for Microbiology 2012 EUKARYOTIC CELL Vol.11 No.11
<B>ABSTRACT</B><P> Heterotrimeric G proteins (G proteins) govern growth, development, and secondary metabolism in various fungi. Here, we characterized <I>ricA</I> , which encodes a putative GDP/GTP exchange factor for G proteins in the model fungus Aspergillus nidulans and the opportunistic human pathogen Aspergillus fumigatus . In both species, <I>ricA</I> mRNA accumulates during vegetative growth and early developmental phases, but it is not present in spores. The deletion of <I>ricA</I> results in severely impaired colony growth and the total (for A. nidulans ) or near (for A. fumigatus ) absence of asexual sporulation (conidiation). The overexpression (OE) of the <I>A. fumigatus ricA</I> gene (Af <I>ricA</I> ) restores growth and conidiation in the ΔAn <I>ricA</I> mutant to some extent, indicating partial conservation of RicA function in Aspergillus . A series of double mutant analyses revealed that the removal of RgsA (an RGS protein of the GanB Gα subunit), but not <I>sfgA</I> , <I>flbA</I> , <I>rgsB</I> , or <I>rgsC</I> , restored vegetative growth and conidiation in ΔAn <I>ricA</I> . Furthermore, we found that RicA can physically interact with GanB in yeast and <I>in vitro</I> . Moreover, the presence of two copies or OE of <I>pkaA</I> suppresses the profound defects caused by ΔAn <I>ricA</I> , indicating that RicA-mediated growth and developmental signaling is primarily through GanB and PkaA in A. nidulans . Despite the lack of conidiation, <I>brlA</I> and <I>vosA</I> mRNAs accumulated to normal levels in the Δ <I>ricA</I> mutant. In addition, mutants overexpressing <I>fluG</I> or <I>brlA</I> (OE <I>fluG</I> or OE <I>brlA</I> ) failed to restore development in the ΔAn <I>ricA</I> mutant. These findings suggest that the commencement of asexual development requires unknown RicA-mediated signaling input in A. nidulans . </P>
Rho, Won-Yeop,Choi, Jung-Woo,Lee, Hea-Yeon,Kyeong, San,Lee, Sang Hun,Jung, Heung Su,Jung, Seunho,Sung, Yung-Eun,Lee, Yoon-Sik,Jun, Bong-Hyun The Royal Society of Chemistry 2014 NEW JOURNAL OF CHEMISTRY Vol.38 No.3
<P>A dye-sensitized solar cell (DSSC) was fabricated using silica-coated quantum dot-embedded silica nanoparticles (SiO<SUB>2</SUB>/QD/SiO<SUB>2</SUB> NPs) as a light-harvesting layer. Compared to an unmodified DSSC, the power conversion efficiency of a DSSC with SiO<SUB>2</SUB>/QD/SiO<SUB>2</SUB> NPs (SiO<SUB>2</SUB>/QD/SiO<SUB>2</SUB> DSSC) increased from 3.92% to 4.82%, an enhancement of approximately 23.0%.</P> <P>Graphic Abstract</P><P>A dye-sensitized solar cell (DSSC) was fabricated using silica-coated quantum dot-embedded silica nanoparticles as a light-harvesting layer. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c3nj01345f'> </P>
Park, Heylin,Jung, Seunho WILEY-VCH Verlag 2005 Electrophoresis Vol.26 No.20
<P>Neutral cyclosophoraoses (Cys) and highly sulfated cyclosophoraoses (HS-Cys) were successfully applied as chiral selectors with SDS for the separation of some chiral flavonoids in MEKC. HS-Cys were synthesized by the chemical modification of a family of neutral Cys isolated from a soil microorganism, Rhizobium meliloti 2011. Chiral catechin was separated with a resolution (R<SUB>s</SUB>) of 0.754 by neutral Cys and SDS. In the case of isosakuranetin and neohesperidin, resolution (R<SUB>s</SUB>) values of 1.483 and 1.306 were obtained with HS-Cys and SDS, respectively.</P>