Program in Biotechnology, Faculty of Science, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Research Unit in Bioconversion/Bioseparation for Value-Added Chemical Production, Institute of Biotechnology and Genetic Engineering, Chulalongkorn University, 254 Phayathai Road, Pathumwan, Bangkok, 10330, Thailand.
Sci Rep. 2022 Mar 18;12(1):4659. doi: 10.1038/s41598-022-08380-0.
It is anticipated that calcium-chelating peptides may serve to enhance the absorption of calcium. This research examined defatted lemon basil seeds (DLBS) which had been treated with Alcalase under optimized parameters for the degree of hydrolysis for proteolysis, discovering that the activity for calcium-binding in a competitive condition with phosphate ion was 60.39 ± 1.545%. The purification of the hydrolysates was performed via ultrafiltration along with reversed-phase high performance liquid chromatography (RP-HPLC). Determination of the purified peptide amino acid sequence was confirmed for both peptides and reported as Ala-Phe-Asn-Arg-Ala-Lys-Ser-Lys-Ala-Leu-Asn-Glu-Asn (AFNRAKSKALNEN; Basil-1), and Tyr-Asp-Ser-Ser-Gly-Gly-Pro-Thr-Pro-Trp-Leu-Ser-Pro-Tyr (YDSSGGPTPWLSPY; Basil-2). The respective activities for calcium-binding were 38.62 ± 1.33%, and 42.19 ± 2.27%. Fluorescence spectroscopy, and fourier transform infrared spectroscopy were employed in order to assess the chelating mechanism between calcium and the peptides. It was found that the calcium ions took place through the activity of the amino nitrogen atoms and the oxygen atoms on the carboxyl group. Moreover, both of these peptides served to improve calcium transport and absorption in Caco-2 cell monolayers, depending on the concentration involved. It was revealed that the peptide-calcium complexes offered an increased calcium absorption percentage when compared to free calcium at similar concentrations. It might be concluded that the peptide within the peptide-calcium complex can promote calcium absorption through both active and passive transport pathways by increasing calcium concentration and promoting cell membrane interaction. Accordingly, DLBS protein can be considered a strong potential source of protein which can be used to produce calcium-binding peptides and might therefore play a role in the production of nutraceutical foods as a bioactive ingredient.
预计钙螯合肽可用于增强钙的吸收。本研究考察了经 Alcalase 处理的脱脂柠檬罗勒籽（DLBS），在水解度的优化参数下进行蛋白水解，发现其在与磷酸离子竞争条件下与钙结合的活性为 60.39±1.545%。水解产物通过超滤和反相高效液相色谱（RP-HPLC）进行纯化。确定了两种肽的纯化肽氨基酸序列，并报告为 Ala-Phe-Asn-Arg-Ala-Lys-Ser-Lys-Ala-Leu-Asn-Glu-Asn（AFNRAKSKALNEN；罗勒-1）和 Tyr-Asp-Ser-Ser-Gly-Gly-Pro-Thr-Pro-Trp-Leu-Ser-Pro-Tyr（YDSSGGPTPWLSPY；罗勒-2）。钙结合的相应活性分别为 38.62±1.33%和 42.19±2.27%。荧光光谱和傅里叶变换红外光谱用于评估肽与钙之间的螯合机制。结果发现，钙离子通过氨基酸氮原子和羧基上氧原子的活性发生作用。此外，这两种肽都能提高 Caco-2 细胞单层中的钙转运和吸收，这取决于所涉及的浓度。结果表明，与相似浓度的游离钙相比，肽-钙复合物提供了更高的钙吸收百分比。可以得出结论，肽-钙复合物中的肽可以通过增加钙浓度和促进细胞膜相互作用，通过主动和被动转运途径促进钙吸收。因此，DLBS 蛋白可以被认为是一种强有力的蛋白质来源，可以用来生产钙结合肽，因此可以作为生物活性成分在营养食品的生产中发挥作用。
