Lv Ying, Liu Qi, Bao Xiaolan, Tang Wuxia, Yang Baichong, Guo Shuntang
College of Food Science & Nutritional Engineering, China Agricultural University, Haidian District, Beijing, China.
J Agric Food Chem. 2009 Jun 10;57(11):4593-7. doi: 10.1021/jf9000204.
The iron-chelating peptides from soybean protein hydrolysates (SPH) were investigated using immobilized metal affinity chromatography (IMAC). The results demonstrated that SPH could absorb on the IMAC-Fe(3+) column, while the capability of the binding iron was different in SPH (10-30 kDa), SPH (3-10 kDa), and SPH (1-3 kDa). The highest binding amount on the column occurred with SPH (10-30 kDa). With the IMAC method, the iron-chelating peptides were shown to be formed at pH lower than 5.5, and they were not affected by NaCL with the concentration between 0.1 mol/L and 1 mol/L, while the iron-chelating peptides could be partially disrupted by 0.02 mol/L Na(2)HPO(4) at pH 8.0. Furthermore, the iron-chelating peptides were identified with reversed phase (RP)-HPLC, SDS-PAGE, and MALDI-TOF MS/MS. The binding characteristics of the SPH on IMAC-Fe(3+) and the sequences of the iron-chelating peptides revealed that binding sites between SPH and iron might be the carboxyl groups of Glu and Asp residues.
采用固定化金属亲和色谱法（IMAC）对大豆蛋白水解物（SPH）中的铁螯合肽进行了研究。结果表明，SPH能够吸附在IMAC-Fe(3+)柱上，然而不同分子量范围的SPH（10-30 kDa）、SPH（3-10 kDa）和SPH（1-3 kDa）结合铁的能力有所不同。在柱上结合量最高的是SPH（10-30 kDa）。采用IMAC方法显示，铁螯合肽在pH低于5.5时形成，并且在0.1 mol/L至1 mol/L浓度的NaCl溶液中不受影响，而在pH 8.0时，0.02 mol/L的Na₂HPO₄可使铁螯合肽部分解离。此外，通过反相（RP）-HPLC、SDS-PAGE和MALDI-TOF MS/MS对铁螯合肽进行了鉴定。SPH在IMAC-Fe(3+)上的结合特性以及铁螯合肽的序列表明，SPH与铁之间的结合位点可能是Glu和Asp残基的羧基。
