蚕蛹源肽锌纳米粒子的制备及其结构表征

Preparation and Characterization of Silkworm Pupa Source Peptide-zinc Nanoparticles

为开发安全易吸收的补锌制剂,提升蚕蛹的利用价值,通过酶解蚕蛹蛋白制备蚕蛹肽,并将其与锌螯合生成肽锌螯合物。以锌螯合能力为指标,确定蚕蛹肽的酶解制备工艺及蚕蛹肽锌螯合物的制备工艺,采用紫外光谱、荧光光谱、扫描电镜、元素分析仪、粒径分析及红外光谱等技术对螯合前后的样品进行结构表征。结果表明,酶解制备蚕蛹肽的条件为碱性蛋白酶加酶量为1%、pH8.0、温度50℃、酶解时间6 h,该条件下的螯合率达58.05%;肽锌纳米粒的最佳制备条件为肽锌质量比1:0.5、pH6.5,温度55℃,时间20 min,此时螯合率达72.63%;添加硫酸锌后,紫外光谱与荧光光谱强度的减弱显示Zn^(2+)与蚕蛹肽成功的发生了结合,所得蚕蛹肽-锌螯合物为粒径71.99 nm的纳米粒子,表面呈均匀的颗粒状结构,锌相对含量达37.46%,肽链中的-COOH、-NH_(2)和-C=O是锌离子与蚕蛹肽的主要结合位点。综上,蚕蛹是制备肽锌螯合物的良好原材料,这为丰富有机锌补充剂资源库和蚕蛹综合利用奠定了一定的理论基础。

Silkworm pupa peptide(SCP)was prepared by enzymatic hydrolysis and then chelated with soluble zinc ions to obtain silkworm pupa peptide-zinc chelates(SCP-Zn),so as to develop safe and easily absorbable zinc supplements and improve the utilization value of silkworm pupa.Taking the zinc chelating capacity as an index,the optimum preparation process of SCP-Zn was determined,and the structure of both SCP and SCP-Zn were characterized by ultraviolet spectrum,fluorescence spectra,scanning electron microscopy,elemental analysis,particle size analysis and Fourier transform infrared spectrum.The results showed that the chelation rate of silkworm chrysalis peptide was 58.05%under the conditions of 1%alkaline protease plus enzyme,pH8.0,temperature 50℃and enzymatic hydrolysis time 6 h.The optimum preparation conditions for preparation of SCP-Zn nanoparticles were as follows:Mass ratio of zinc peptide 1:0.5,pH6.5,55℃,time 20 min,and the chelation rate of zinc reached 72.63%.The results of ultraviolet spectrum and fluorescence spectrum showed that zinc ions successfully combined with SCP.The obtained chrysalis SCP-Zn belongs to nanoparticles with an average particle size of 71.99 nm,with uniform granular structure on the surface,and the relative content of zinc reached 37.46%.The-COOH,-NH_(2) and-C=O in the peptide chain were the main binding sites of Zn^(2+)and SCP.The results indicated that silkworm pupa was a good raw material for preparation of zinc chelates.The study provides a theoretical basis for enriching organic zinc supplement resources and the high value utilization of silkworm pupa.