Abstract A selenium-chelating corn oligopeptide (Se-COP) with high protein and low molecular weight was prepared as a selenium supplement. We utilized infrared (IR), ultraviolet (UV), and circular dichroism (CD) spectroscopy, 1-anilinonaphthalene-8-sulfonate (ANS)-binding fluorescence spectra, and isothermal titration calorimetry (ITC) to analyze and describe Se-COP and its reactions. It was concluded that the chelation reaction was a spontaneous process driven by enthalpy and entropy, with ΔH=3.79 × 104 ± 4075 cal/mol, ΔS = 146 cal/mol, ΔG = –23356.30 ± 126.94 cal/mol, binding constant Ka = 1.18 × 104 ± 855 M–1, and binding site number n = 0.13 ± 0.0126, and described as coordination bonds forming and hydrophobic interaction, as well as protein conformational changes including secondary and tertiary hydrophobic structure. Se-COP had strong antioxidant capacity, and mass spectrometry (MS) was used to identify the antioxidant peptide fragment, which was characterized as LLPPY and quantified at 428.95 ng/mg. This study indicated that Se-COP prepared by chelation may be a Se supplement with antioxidant capacity that can be applied in functional foods or ingredients.

中文翻译：

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硒螯合玉米寡肽作为潜在的抗氧化补充剂：蛋白质构象变化的研究和抗氧化片段组成的鉴定

摘要 制备了一种高蛋白、低分子量的硒螯合玉米寡肽（Se-COP）作为硒补充剂。我们利用红外 (IR)、紫外 (UV) 和圆二色性 (CD) 光谱、1-苯胺萘-8-磺酸盐 (ANS) 结合荧光光谱和等温滴定量热法 (ITC) 来分析和描述 Se-COP 和它的反应。得出的结论是螯合反应是一个由焓和熵驱动的自发过程，ΔH=3.79 × 104 ± 4075 cal/mol，ΔS = 146 cal/mol，ΔG = –23356.30 ± 126.94 cal/mol，结合常数Ka = 1.18 × 104 ± 855 M–1，结合位点数 n = 0.13 ± 0.0126，描述为配位键形成和疏水相互作用，以及蛋白质构象变化，包括二级和三级疏水结构。Se-COP具有很强的抗氧化能力，通过质谱（MS）鉴定抗氧化肽片段，其特征为LLPPY，定量为428.95 ng/mg。本研究表明螯合制备的Se-COP可能是一种具有抗氧化能力的硒补充剂，可应用于功能性食品或配料中。