School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150090, China.
School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
J Dairy Sci. 2020 May;103(5):3950-3960. doi: 10.3168/jds.2019-17425. Epub 2020 Mar 18.
Osteoporosis is a disease of aging, characterized by a decrease in bone quality and a reduction in bone strength. Promoting the activity of osteoblasts is a useful strategy for combating the progression of osteoporosis. As a novel bone growth factor, lactoferrin plays a role in the anabolic activity in bone by inducing the proliferation and differentiation of osteoblasts and inhibiting the formation of osteoclasts. However, potential peptides with osteogenic activity from lactoferrin have not been identified. In the present study, a peptide with osteogenic activity-LFP-C, fragment residues 624 to 632, derived from lactoferrin hydrolysates-was identified using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry and screened using molecular docking analysis. The LFP-C peptide significantly increased the proliferation of mouse cell line MC3T3-E1 and had a promoting effect on alkaline phosphatase activity and calcium deposition. Moreover, LFP-C increased the proportion of osteoblasts in the G and M phases. The osteogenic mechanism of LFP-C was also studied by molecular docking. We found that LFP-C could bind to the key domain (Lys13-Thr15-Gln16-Leu17-Gly18-Asp22) of epidermal growth factor receptor, a vital receptor tyrosine kinase that leads to the activation of the mitogen-activated protein kinase pathway. The main interaction forces were interpolated charge, hydrophobicity, and hydrogen bonding. Results indicated that LFP-C may play an osteogenic role in a similar way to lactoferrin, by promoting the proliferation and differentiation of osteoblasts. The findings of this in vitro experiment also demonstrated that the molecular docking method could play a role in the screening process; this in silico approach allowed for faster and cheaper identification of a promising bioactive component.
骨质疏松症是一种衰老性疾病，其特征是骨质量下降和骨强度降低。促进成骨细胞的活性是对抗骨质疏松症进展的有效策略。乳铁蛋白作为一种新型的骨生长因子，通过诱导成骨细胞的增殖和分化，抑制破骨细胞的形成，在骨的合成代谢活性中发挥作用。然而，尚未从乳铁蛋白中鉴定出具有成骨活性的潜在肽。在本研究中，使用超高效液相色谱/四极杆飞行时间质谱法鉴定了一种具有成骨活性的肽-LFP-C，其来源于乳铁蛋白水解物的片段残基 624 至 632，并用分子对接分析进行了筛选。LFP-C 肽显著增加了小鼠细胞系 MC3T3-E1 的增殖，并对碱性磷酸酶活性和钙沉积有促进作用。此外，LFP-C 增加了处于 G 期和 M 期的成骨细胞的比例。还通过分子对接研究了 LFP-C 的成骨机制。我们发现 LFP-C 可以与表皮生长因子受体（一种关键的受体酪氨酸激酶）的关键域（Lys13-Thr15-Gln16-Leu17-Gly18-Asp22）结合，导致丝裂原激活的蛋白激酶途径的激活。主要的相互作用力是穿插电荷、疏水性和氢键。结果表明，LFP-C 可能通过促进成骨细胞的增殖和分化，以类似于乳铁蛋白的方式发挥成骨作用。该体外实验的结果还表明，分子对接方法可在筛选过程中发挥作用；这种计算方法可以更快、更便宜地鉴定有前途的生物活性成分。
