Natural Products & Green Chemistry Division, CSIR-Central Salt & Marine Chemicals Research Institute, G. B Marg, Bhavnagar, 364002, Gujarat, India; AcSIR-Central Salt & Marine Chemicals Research Institute, G. B Marg, Bhavnagar, 364002, Gujarat, India.
CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
Int J Biol Macromol. 2018 Dec;120(Pt A):378-384. doi: 10.1016/j.ijbiomac.2018.08.102. Epub 2018 Aug 23.
Packaging of structurally sensitive biomolecules such as proteins, peptides and DNA in non-aqueous media at ambient conditions with chemical and structural stability is important to explore the potential of such biomacromolecules as substrate for functional biomaterial design and for biotechnological applications. In this perspective, solubility, chemical and structural stability of ɛ-poly-l-lysine (ɛ-PL), a homopolypeptide produced by Streptomyces albulus in different ionic liquids (ILs) namely 2-hydroxyethyl ammonium formate (2-HEAF), 2-hydroxyethyl ammonium acetate (2-HEAA), choline formate (Ch-Formate) and choline acetate (Ch-Acetate) was studied. Maximum solubility (15% w/v) of the homopolypeptide was observed in 2-HEAF and lowest was found in Ch-Formate (2% w/v). After regeneration of the dissolved polypeptide in the IL, the IL could be recycled and reused in the dissolution process. Unlike in other ILs, 3-15% w/v of ɛ-PL in 2-HEAF gave formation of a thixotropic thermoreversible soft gel. Molecular docking studies established favourable interactions of [2-HEA] cation over [Ch] with ɛ-PL indicating [2-HEA] as the most promising cation for the dissolution process. However, the role of the anions was also found to be important, which could lead to improvement in polypeptide solubility when combined to the selected cation. The findings demonstrate suitability of the ionic liquids for functionalization of polypeptides for biomaterial preparation.
在环境条件下，将蛋白质、肽和 DNA 等结构敏感生物分子包装在非水介质中，并保持其化学和结构稳定性，对于探索这些生物大分子作为功能生物材料设计和生物技术应用的底物的潜力非常重要。从这个角度来看，我们研究了由 Streptomyces albulus 产生的均聚物 ε-聚-L-赖氨酸（ε-PL）在不同离子液体（ILs）中的溶解度、化学和结构稳定性，这些 ILs 分别为甲酸 2-羟乙基铵（2-HEAF）、乙酸 2-羟乙基铵（2-HEAA）、甲酸胆碱（Ch-Formate）和乙酸胆碱（Ch-Acetate）。该均聚物的最大溶解度（15%w/v）出现在 2-HEAF 中，最低溶解度（2%w/v）出现在 Ch-Formate 中。在将溶解的多肽在 IL 中再生后，IL 可以回收并重复用于溶解过程。与其他 IL 不同的是，在 2-HEAF 中，3-15%w/v 的 ε-PL 形成了一种触变热可逆软凝胶。分子对接研究表明，[2-HEA]阳离子与 ε-PL 之间存在有利的相互作用，表明[2-HEA]阳离子最适合用于溶解过程。然而，阴离子的作用也被发现是重要的，当与所选阳离子结合时，可能会提高多肽的溶解度。这些发现表明离子液体适用于多肽的功能化，以制备生物材料。
