A Non-Native a-Helix Is Formed in the ?-Sheet Region of the Molten Globule State of Canine Milk Lysozyme

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• 作者：Masahiro Watanabe ; Yoshihiro Kobashigawa ; Tomoyasu Aizawa ; Makoto Demura and Katsutoshi Nitta
• 关键词：Canine milk lysozyme ; CD spectroscopy ; cooperativity ; helical propensity ; non ; native ; helix
• 刊名：The Protein Journal
• 出版年：2004
• 出版时间：July 2004
• 年：2004
• 卷：23
• 期：5
• 页码：335-342
• 全文大小：126 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Bioorganic Chemistry
  Biochemistry
  Organic Chemistry
  Animal Anatomy, Morphology and Histology
  
• 出版者：Springer Netherlands
• ISSN：1573-4943

文摘

The native and the molten globule states (N and MG states, respectively) of canine milk lysozyme (CML) were examined by CD spectroscopy and AGADIR algorithm, a helix-coil transition program. It revealed that the helical content of the MG state was higher than that of the N-state, suggesting that non-native -helix is formed in the MG state of CML. Using AGADIR, it indicated the possibility of -helix formation in the third -strand region in the MG state. To investigate this possibility, we designed a mutant, Q58P, in which the helical propensity of the MG state was significantly decreased around the third -strand region. It appeared that the absolute ellipticity value at 222 nm of the mutant in the MG state was smaller than that of the wild-type protein. It could be assumed that the non-native -helix is formed around the third -strand region of wild-type CML in the MG state.