School of Bioengineering and Biosciences, Lovely Professional University, Jalandhar, Punjab, 144001, India.
Biomedical Engineering, School of Health Sciences, Birmingham City University, Seacole Building, 32 Westbourne Road, Birmingham, B15 3TN, UK.
Amino Acids. 2022 Mar;54(3):411-419. doi: 10.1007/s00726-022-03138-4. Epub 2022 Feb 22.
Profilin protein is present ubiquitously in all forms of life and is allied with allergic responses among atopic individuals. In addition to this, profilins from various food sources are also associated with IgE cross-reactivity and are thus classified as pan-allergens. The present study unravels the physicochemical basis of differential amino acid usage patterns observed in the profilin gene family. Correspondence analysis based on amino acid usage of allergen and non-allergen profilins revealed discrete clusters among them, signifying differential patterns of amino acid usage. The amino acids, namely methionine, proline, histidine, glutamine, glutamic acid, tryptophan and glycine were found to be more frequently utilised by the allergen profilins compared to the non-allergens. Correlation analysis revealed that physicochemical features like protein disorder, trypsin digestion and solubility differed significantly among the allergen and non-allergen profilins, thus supporting the observations from correspondence analysis. In addition, comprehensive sequence analysis revealed that the allergen profilins possess conserved motifs which may correlate with their distinct physicochemical features. An in-depth structural analysis revealed that the over-represented amino acids in allergen profilins have a propensity of being exposed on the surface, which may be attributed to their distinct allergenic characteristics. The distinguished physicochemical features observed among allergens and non-allergens can be employed as descriptors to develop machine learning-based allergenicity prediction models.
丝状蛋白在所有生命形式中普遍存在，与特应性个体的过敏反应有关。此外，来自各种食物来源的丝氨酸也与 IgE 交叉反应有关，因此被归类为泛过敏原。本研究揭示了丝氨酸基因家族中观察到的差异氨基酸使用模式的理化基础。基于过敏原和非过敏原丝氨酸的氨基酸使用的对应分析揭示了它们之间离散的聚类，表明了氨基酸使用的差异模式。与非过敏原丝氨酸相比，过敏原丝氨酸中更频繁地使用了氨基酸，如蛋氨酸、脯氨酸、组氨酸、谷氨酰胺、谷氨酸、色氨酸和甘氨酸。相关性分析表明，过敏原和非过敏原丝氨酸在蛋白质无序性、胰蛋白酶消化和溶解度等理化特性方面存在显著差异，这支持了对应分析的观察结果。此外，全面的序列分析表明，过敏原丝氨酸具有保守的基序，这可能与其独特的理化特性相关。深入的结构分析表明，过敏原丝氨酸中过度表达的氨基酸倾向于暴露在表面，这可能归因于它们独特的致敏特性。过敏原和非过敏原之间观察到的有区别的理化特性可以用作描述符，以开发基于机器学习的致敏性预测模型。
