Biophysical Chemistry, ( ISI ), Volume (122), No (122), Year (2006-12) , Pages (58-65)

Title : Comparison of the molten globule states of thermophilic and mesophilic α-amylases ( Comparison of the molten globule states of thermophilic and mesophilic α-amylases )

Authors: Maryam Monsef Shokri , Khosro Khajeh , Jahan Alikhajeh , Ahmad Asoodeh , Bijan Ranjbar , Saman Hosseinkhani , Mehdi Sadeghi ,

Access to full-text not allowed by authors

Citation: BibTeX | EndNote

In recent years great interest has been generated in the process of protein folding, and the formation of intermediates during the folding process has been proven with new experimental strategies. In the present work, we have examined the molten globule state of Bacillus licheniformis α- amylase (BLA) by intrinsic fluorescence and circular dichroism spectra, 1-anilino naphthalene-8-sulfonate (ANS) binding and proteolytic digestion by pepsin, for comparison to its mesophilic counterpart, Bacillus amyloliquefaciens α-amylase (BAA). At pH 4.0, both enzymes acquire partially folded state which show characteristics of molten globule state. They unfold in such a way that their hydrophobic surfaces are exposed to a greater extent compared to the native forms. Chemical denaturation studies by guanidine hydrochloride and proteolytic digestion with pepsin show that molten globule state of BLA is more stable than from BAA. Results from gel filtration indicate that BAA has the same compactness at pH 4.0 and 7.5. However, molten globule state of BLA is less compact than its native state. The effects of polyols such as trehalose, sorbitol and glycerol on refolding of enzymes from molten globule to native state were also studied. These polyols are effective on refolding of mesophilic α- amylase but only slightly effect on BLA refolding. In addition, the folding pathway and stability of intermediate state of the thermophilic and the mesophilicα-amylases are discussed.

Keywords

, α-amylases, hermophilic, mesophilicα, molten globule
برای دانلود از شناسه و رمز عبور پرتال پویا استفاده کنید.

@article{paperid:102294,
author = {Maryam Monsef Shokri and Khosro Khajeh and Jahan Alikhajeh and Asoodeh, Ahmad and Bijan Ranjbar and Saman Hosseinkhani and Mehdi Sadeghi},
title = {Comparison of the molten globule states of thermophilic and mesophilic α-amylases},
journal = {Biophysical Chemistry},
year = {2006},
volume = {122},
number = {122},
month = {December},
issn = {0301-4622},
pages = {58--65},
numpages = {7},
keywords = {α-amylases; hermophilic; mesophilicα; molten globule state},
}

[Download]

%0 Journal Article
%T Comparison of the molten globule states of thermophilic and mesophilic α-amylases
%A Maryam Monsef Shokri
%A Khosro Khajeh
%A Jahan Alikhajeh
%A Asoodeh, Ahmad
%A Bijan Ranjbar
%A Saman Hosseinkhani
%A Mehdi Sadeghi
%J Biophysical Chemistry
%@ 0301-4622
%D 2006

[Download]