• Title/Summary/Keyword: CD spectra

Search Result 283, Processing Time 0.019 seconds

Studies on Antitumor Components of Collybia confluens (밀버섯의 항암성분에 관한 연구)

  • Kim, Sook-Hee;Kim, Jin-Sook;Jin, Mi-Rim;Kim, Ha-Won;Choi, Eung-Chil;Kim, Byong-Kak
    • Korean Journal of Pharmacognosy
    • /
    • v.24 no.4
    • /
    • pp.267-281
    • /
    • 1993
  • To find antitumor components from higher fungi, the mycelia of Collybia confluens (Pers. ex Fr.) Kummer were cultured in artificial media. For efficient production of the mycelia, the influences of various modifications of culture conditions were examined. A water-soluble protein-bound polysaccharide fraction, Fr. A, was obtained from the mycelia by hot water extraction. When Fr. A was purified and fractionated by DEAE-cellulose and Sepbadex G-200 gel filtration chromatographies into four fractions which were designated B, C, C-I and C-II. The tumor inhibition ratios of these fractions ranged from 46% to 75% against the solid forms of sarcoma 180 in ICR mice at doses of 20 and 50 mg/kg/day when given intraperitoneally. Especially, Fr. C which was named Collyban(CB) exhibited a marked life-prolonging effect of the mice against ascitic forms of sarcoma 180 at a dose of 50 mg via i.p. administration. To extend spectra of the antitumor activities and eliminate the effects of allograft rejection, the characterization of antitumor effects of CB was performed in syngeneic host-tumor systems. It did not show any antitumor activity against L1210 murine leukemia in $CD_2Fl$ mice but prolonged their life span against ascitic forms of $MM_{46}$ carcinoma in $C_3H/He$ mice. Also it exhibited antitumor activity against human cervical cancer HeLa cells that were xenografted into nude mice having BALB/c genetic backgrounds by the i.p. injection at a dose of 100 mg/kg/day. In order to characterize the antitumor components, CB was examined by chemical analysis. It was acidic protein-bound polysaccharides composed of 31% polysaccharide, 27% protein and 3% hexosamine. CB was fractionated into two fractions, Fr. C-I(M.W.: 500 Kd) and Fr. C-II(M.W.:30 and 8 Kd) by Sephadex G-200 gel filtration chromatography.

  • PDF

Biochemical Characteristics for the Cofactor Free Mutant of Yeast Homocysteine Catalyzing Enzyme, Cystathionine ${\beta}$-Synthase (조효소를 함유하지 않는 효모의 Homocysteine 분해효소, Cystathionine ${\beta}$-Synthase의 생화학적 특성)

  • Jhee, Kwang-Hwan;Cho, Hyun-Nam;Yang, Seun-Ah;Lee, In-Seun
    • Microbiology and Biotechnology Letters
    • /
    • v.35 no.3
    • /
    • pp.196-202
    • /
    • 2007
  • Mutations in the cystathionine ${\beta}$-synthase (CBS) gene cause homocystinuria, the most frequent inherited disorder in sulfur metabolism. CBS is the unique enzyme using both heme and pyridoxal 5-phosphate (PLP) for activity. Among the reported 140 mutations, one of the most common disease-causing alterations in human CBS is G307S mutation. To investigate the pathogenic mechanism of G307S by spectroscopic methods, we engineered the full length and the truncated G247S mutation of yeast CBS that is corresponding mutation to human G307S. Yeast CBS does not contain heme and thus gives a merit to study the spectroscopic properties. The UV-visible spectra of the purified full length and the truncated G247S yeast CBSs showed the total absence of PLP in the protein. The absence of PLP in G247S mutation was also confirmed by the PLP-cyanide adduct formation experiment, which was conducted by the incubation of the purified enzyme with KCN. The adducts were detected using a circular dichroism (CD) and a spectrofluorimeter. Radio isotope activity assay of full length and truncated G247S proteins also gave no activity. Our yeast G247S mutation data suggested that G307S might make the distortion of the active site so that cofactor PLP and substrate can not fit inside the active site. Our yeast CBS study addressed the reason why the G307S mutation in human CBS makes the enzyme inactive that consequently leads to severe clinical phenotype.

Synthesis of Heptadentate Nitrogen-Oxygen Ligands (N4O3) with Substituting Groups and Determination of Stability Constants of Their Transition Metal(II) Complexes (치환기를 가진 일곱 자리 질소-산소(N4O3)계 리간드 합성과 전이금속(II) 이온 착물의 안정도상수 결정)

  • Kim, Sun-Deuk;Lee, Do-Hyub;Seol, Jong-Min
    • Journal of the Korean Chemical Society
    • /
    • v.54 no.5
    • /
    • pp.541-550
    • /
    • 2010
  • A new $N_4O_3$ heptadentate ligand, N,N'-Bis(2-hydroxybenzyl)-1,3-bis[(2-aminoethyl)amino]-2-propanol(H-BAP 4HCl)was synthesized. The hydrochloric acid salts of Br-BAP 4HCl, Cl-BAP 4HCl, $CH_3O$-BAP 4HCl and $CH_3$-BAP 4HCl containing Br-, Cl-, H-, $CH_3O-$ and $CH_{3^-}$ groups at the para-site of the phenol group of the H-BAP were synthesized. The structures of the ligands were confirmed by C. H. N. atomic analysis and $^1H$ NMR, $^{13}C$ NMR, UV-visible and mass spectra. The elemental stepwise protonation constants(${logK_n}^H$) of the synthesized $N_4O_3$ ligands showed six steps of the proton dissociation. The orders of the overall dissociation constants($log{\beta}_p$) of the ligands were Br-BAP < Cl-BAP < H-BAP < $CH_3O$-BAP < $CH_3$-BAP. The orders agreed well with that of Hammett substituent constants($\sigma_p$). The calculated stability constants($logK_{ML}$) between the ligands and transition metal ions agreed well with the order of the overall proton dissociation constants of the ligands but they showed a reverse order in Hammestt substituent constants($\sigma_p$). The order of the stability constants between the transition metal ions with the ligands were Co(II) < Ni(II) < Cu(II) > Zn(II) > Cd(II) > Pb(II).