TU Dortmund University, Department of Biochemical and Chemical Engineering, Laboratory of Plant and Process Design, Dortmund, Germany.
Evonik Technology & Infrastructure GmbH, Rodenbacher Chaussee 4, 63457, Hanau, Wolfgang, Germany.
J Biotechnol. 2021 Jun 20;334:11-25. doi: 10.1016/j.jbiotec.2021.05.002. Epub 2021 May 18.
Their surface activity enables proteins to form and stabilize foam, which can be used for in situ product separation or foam fractionation. Thus, it would be highly desirable to predict the surface activity of proteins based on their molecular properties like hydrophobicity, amphilicity, or structure on primary, secondary, and tertiary level. Ionic strength and pH were adjusted to gain maximum surface activity. The surface activity decreased in the order α lactalbumin > β‑lactoglobulin > trypsinogen > papain. For the theoretical analysis, the database was extended by including 2 hydrophobins into the investigation, since they are known to exhibit an outstanding surface activity. No relation to the macroscopic behavior was found considering the hydrophobicity. I.e., the non-hydrophobins did not differ significantly from each other, and from the hydrophobins, one was significantly hydrophobic, and the other was significantly hydrophilic. Also, no relations were found considering the amphilicity of the secondary structure elements. However, taking into account the tertiary protein structure, it was found that for most of the proteins investigated, the presence of non-buried amphiphilic secondary structure elements in combination with a certain amount of flexibility correlates with the surface activity.
它们的表面活性使蛋白质能够形成和稳定泡沫，可用于就地产品分离或泡沫分级。因此，根据蛋白质的分子特性，如疏水性、两亲性或一级、二级和三级结构，预测其表面活性将是非常理想的。调节离子强度和 pH 值以获得最大的表面活性。表面活性按α乳白蛋白>β-乳球蛋白>胰蛋白酶原>木瓜蛋白酶的顺序降低。为了进行理论分析，通过将 2 种疏水性蛋白纳入研究范围，扩展了数据库，因为它们已知具有出色的表面活性。考虑疏水性时，没有发现与宏观行为有关。即，非疏水性蛋白彼此之间以及与疏水性蛋白之间没有明显差异，其中一个疏水性显著，另一个亲水性显著。此外，考虑二级结构元件的两亲性时也没有发现关系。然而，考虑到三级蛋白质结构，发现对于大多数研究的蛋白质，存在非埋藏的两亲性二级结构元件与一定程度的灵活性相结合，与表面活性相关。
