Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Request Permissions
Google Scholar
Right arrow Articles by Le, W.-P.
Right arrow Articles by Zhou, H.-M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Le, W.-P.
Right arrow Articles by Zhou, H.-M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

J. Biochem, 1996, Vol. 119, No. 4 674-679
© 1996 Japanese Biochemical Society

research-article

Acid-Induced Folding of Yeast Alcohol Dehydrogenase under Low pH Conditions1

Wei-Ping Le*, Si-Xu Yan*, Ying-Xia Zhang{dagger},2 and Hai-Meng Zhou{dagger},{ddagger},3

*Department of Biology, Xiamen University Xiamen 361005
{dagger}Department of Biological Science and Biotechnology Tsinghua University, Beijing 100084
{ddagger}National Laboratory of Macromolecules, Institute of Biophysics Academia Sinica, Beijing 100101, China

3To whom correspondence should be addressed.

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.

1The present investigation was supported in part by the Pandeng project of the China Commission for Science and Technology and by Grant 39570180 of the China Natural Science Foundation.

2Present address: Department of Chemistry, Capital University of Medicine Science, Beijing 100054, P.R. China.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.