Acid-Induced Unfolding Process of Myoglobin and Its Mutant under Macromolecular Crowding Conditions

作者：Zhang Yu Jiao; Tang Qian; Cao Hong Yu; Zheng Xue Fang^*

来源：Acta Physico - Chimica Sinica, 2013, 29(8): 1785-U260.

DOI：10.3866/PKU.WHXB201305271

• Crowding agent
• Acid denaturation
• Myoglobin
• Mutant
• Spectrometry

In this paper, we studied the unfolding process of myoglobin (Mb) and its mutant Mb(D60K) induced by acid under macromolecular crowding conditions, using ultraviolet-visible absorption, synchronous fluorescence, and circular dichroism (CD) spectroscopies. The spectroscopic data showed that, with the addition of Dextran70 or Ficoll70, the denaturation midpoint of Mb(WT) decreased from 4.25 to 3.78 or 3.76, respectively. In addition, the acid tolerance of Mb(WT) improved under macromolecular crowding conditions. The denaturation midpoint of Mb(D60K) was 4.19, which was a slight decrease from that of Mb (4.25). Upon addition of Dextran70 or Ficoll70, the denaturation midpoint of Mb(D60K) decreased from 4.19 to 3.74 or 3.12, respectively. The spectroscopic results illustrated that the amino acid mutant and crowding agents could stabilize the microenvironment surrounding the heme and aromatic amino acid as well as the second structure of Mb, protecting its native state.

• 出版日期2013-8
• 单位大连大学