National Institute of Genetic Engineering and Biotechnology, Pajoohesh Blvd., Tehran-Karaj Highway, 17th km, Tehran, Iran.
Appl Biochem Biotechnol. 2010 Apr;160(7):1921-32. doi: 10.1007/s12010-009-8723-8. Epub 2009 Aug 4.
Acid-induced unfolding of a Tetracoccosporium sp. polygalacturonase enzyme (PG) was studied by a comprehensive series of biophysical and biochemical techniques. At pH 1.0, PG acquires partially folded state, which reveals characteristics of molten globule (MG) state, i.e., reduction of defined tertiary structure with minimal changes in the secondary structure. In this study PG unfolds exposing its hydrophobic surface to a greater extent than the native form at acidic pH with more tryptophan residues exposed to the solvent. Collectively, our data imply the presence of MG state of PG at low pH, suggesting the phenomenon of hydrophobic collapse model for folding and integration into cell membrane.
通过一系列全面的生物物理和生化技术研究了 Tetracoccosporium sp. 聚半乳糖醛酸酶（PG）在酸性条件下的展开情况。在 pH 值为 1.0 时，PG 获得部分折叠状态，这揭示了变性球蛋白（MG）状态的特征，即定义的三级结构减少，二级结构变化最小。在这项研究中，PG 展开时暴露其疏水面的程度比在酸性 pH 值下的天然形式更大，更多的色氨酸残基暴露于溶剂中。总的来说，我们的数据表明 PG 在低 pH 值下存在 MG 状态，这表明了折叠和整合到细胞膜中的疏水塌陷模型现象。
