BIOTIN CARBOXY TERMINAL DOMAIN FOLDING CALORIMETRY E COLI ACETYL COA CARBOXYLASE

在生物素依赖性羧化酶中，生物素部分共价连接至羧化酶。 键合到生物素羧基载体（BCC）官能团上， 酶通过酰胺键连接到单个 赖氨酸残基 在大肠大肠杆菌乙酰辅酶A羧化酶 功能性存在于单独的17 kD亚基中。 一个87残基 该亚基的C-末端结构域片段（BCCP 87）已被证明是 在酶催化的酶促反应中， 生物素化反应 高分辨率的结构都载脂蛋白和 域的全息形式是可用的。 的折叠特性。 BCCP 87的apo和holo形式将通过差示扫描进行研究 量热法，以确定贡献，如果有的话， 翻译后修饰的热力学稳定性 蛋白 热力学研究的结果将与 现有的结构数据，以确定结构基础的任何 测量折叠能量学的差异。

In biotin-dependent carboxylases, the biotin moiety is covalently bonded to the Biotin Carboxyl Carrier (BCC) functionality of the enzyme via an amide linkage to the epsilon amino group of a single lysine residue. In E. coli acetyl-CoA carboxylase, the BCC functionality resides in a separate 17 kD subunit. An 87 residue C-terminal domain fragment (BCCP87) of this subunit has been shown to behave identically to the intact protein in the enzyme-catalyzed biotination reaction. High resolution structures of both the apo- and holo-forms of the domain are available. The folding properties of the apo- and holo-forms of BCCP87 will be studied by differential scanning calorimetry to determine the contribution, if any, of a post-translational modification to the thermodynamic stability of the protein. Results of the thermodynamic studies will be combined with the available structural data to determine the structural basis of any measured differences in the energetics of folding.