caa a22 4500 397557310 CHVBK 20180308164806.0 cr unu---uuuuu 161202e199604 xx s 000 0 eng 10.1093/oxfordjournals.jbchem.a021295 doi (NATIONALLICENCE)oxford-10.1093/oxfordjournals.jbchem.a021295 Acid-Induced Folding of Yeast Alcohol Dehydrogenase under Low pH Conditions [Elektronische Daten] [Wei-Ping Le, Si-Xu Yan, Ying-Xia Zhang, Hai-Meng Zhou] Under conditions of low pH, the conformational states of holo-YADH and apo-YADH were examined by protein intrinsic fluorescence, ANS fluorescence, and far-UV CD measurements. The results obtained show that at low ionic strength, with the addition of HC1, the holo- and apo-YADH denatured gradually to reach the ultimate unfolded conformation in the vicinity of pH 2.0 and 2.5, respectively. With the decrease of pH from 7.0 to 2.0, the fluorescence emission decreased markedly, with its emission maximum red-shifting from 335 to 355 nm, indicating complete exposure of the buried tryptophan residues to the solvent. The far-UV CD spectra show the loss of the arrayed secondary structure, though the acid-denatured enzyme still maintained a partially arrayed secondary structure. A further decrease in pH by increasing the concentration of HC1O4 induced a cooperative folding of the denatured enzyme to a compact conformation with the properties of a molten globule, described previously by Goto et al [Proc. Natl. Acad. ScL USA 87, 573-577 (1990)]. More extensive studies snowed that although apo-YADH and holo-YADH exhibited similar behavior, the folding cooperative ability of apo-YADH was lower than that of the holo-en-zyme. From the above results, it is suggested that the zinc ion plays an important role in the proper folding of YADH and in stabilizing its native conformation. © by the Journal of Biochemistry Regular Papers nationallicence alcohol dehydrogenase nationallicence acidic denaturation nationallicence molten globule state nationallicence refolding nationallicence Le Wei-Ping Department of Biology, Xiamen University Xiamen 361005 aut Yan Si-Xu Department of Biology, Xiamen University Xiamen 361005 aut Zhang Ying-Xia Department of Biological Science and Biotechnology Tsinghua University, Beijing 100084 aut Zhou Hai-Meng Department of Biological Science and Biotechnology Tsinghua University, Beijing 100084 aut The Journal of Biochemistry Oxford University Press 119/4(1996-04), 674-679 0021-924X 119:4<674 1996 119 jbchem https://doi.org/10.1093/oxfordjournals.jbchem.a021295 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1093/oxfordjournals.jbchem.a021295 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Le Wei-Ping Department of Biology, Xiamen University Xiamen 361005 aut NATIONALLICENCE 700 1- Yan Si-Xu Department of Biology, Xiamen University Xiamen 361005 aut NATIONALLICENCE 700 1- Zhang Ying-Xia Department of Biological Science and Biotechnology Tsinghua University, Beijing 100084 aut NATIONALLICENCE 700 1- Zhou Hai-Meng Department of Biological Science and Biotechnology Tsinghua University, Beijing 100084 aut NATIONALLICENCE 773 0- The Journal of Biochemistry Oxford University Press 119/4(1996-04), 674-679 0021-924X 119:4<674 1996 119 jbchem Metadata rights reserved CC BY-NC-4.0 http://creativecommons.org/licenses/by-nc/4.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-oxford