酶解法制备方格星虫多肽及其抗氧化作用研究

采用木瓜蛋白酶酶解制备方格星虫多肽,通过单因素实验研究了加酶量、酶解温度、酶解时间、酶解pH值和料液比等因素对羟自由基清除率的影响。通过正交试验确定了木瓜蛋白酶对方格星虫最佳的酶解工艺条件为:加酶量300 U/g,酶解温度50℃,酶解时间60 min,酶解液pH值7.0,料水比1∶3。在此条件下酶解方格星虫获得多肽的羟自由基清除率为95.42%,表明方格星虫酶解物具有较明显的抗氧化能力。由高效体积排阻色谱(HPSEC)法测得方格星虫多肽的分子量为5868。     

Collagen Peptides Derived from Sipunculus nudus Accelerate Wound Healing

Marine collagen peptides have high potential in promoting skin wound healing. This study aimed to investigate wound healing activity of collagen peptides derived from Sipunculus nudus (SNCP). The effects of SNCP on promoting healing were studied through a whole cortex wound model in mice. Results showed that SNCP consisted of peptides with a molecular weight less than 5 kDa accounted for 81.95%, rich in Gly and Arg. SNCP possessed outstanding capacity to induce human umbilical vein endothelial cells (HUVEC), human immortalized keratinocytes (HaCaT) and human skin fibroblasts (HSF) cells proliferation and migration in vitro. In vivo, SNCP could markedly improve the healing rate and shorten the scab removal time, possessing a scar-free healing effect. Compared with the negative control group, the expression level of tumor necrosis factor-α, interleukin-1β and transforming growth factor-β1 (TGF-β1) in the SNCP group was significantly down-regulated at 7 days post-wounding (p < 0.01). Moreover, the mRNA level of mothers against decapentaplegic homolog 7 (Smad7) in SNCP group was up-regulated (p < 0.01); in contrast, type II TGF-β receptors, collagen I and α-smooth muscle actin were significantly down-regulated at 28 days (p < 0.01). These results indicate that SNCP possessed excellent activity of accelerating wound healing and inhibiting scar formation, and its mechanism was closely related to reducing inflammation, improving collagen deposition and recombination and blockade of the TGF-β/Smads signal pathway. Therefore, SNCP may have promising clinical applications in skin wound repair and scar inhibition.     

方格星虫多肽的酶解法制备工艺优化与抗氧化作用研究

分别采用胰蛋白酶、木瓜蛋白酶、胃蛋白酶等8种蛋白酶酶解方格星虫制备方格星虫多肽,通过测定酶的活力和羟自由基清除率,确定以木瓜蛋白酶作为方格星虫多肽的酶解最适酶。通过单因素实验研究了加酶量、酶解温度、酶解时间、酶解pH和料水比等因素对羟自由基清除率的影响,并通过正交试验确定了木瓜蛋白酶对方格星虫优化的酶解工艺为:加酶量300U/g,酶解温度50℃,酶解时间60min,酶解液pH7.0,由此条件酶解,获得的羟自由基清除率为95.42%。结果表明,方格星虫多肽具有很强的清除自由基的能力。     

Effect of polysaccharides extracted from Sipunculus nudus (SNP) on the lifespan and immune damage repair of Drosophila melanogaster exposed to Cd (VI)

The water-soluble polysaccharides extracted from Sipunculus nudus (SNP) was investigated on the lifespan and immune damage repair of Drosophila melanogaster exposed to Cd (VI). SNP increased superoxyde dismutase (SOD), nitrogen monoxide (NO), glutathione peroxidase (GSH-Px) and total anti-oxidation competence (T-AOC), with decreased malondialdehyde (MDA) on D. melanogaster demonstrated that SNP could attenuate oxidative damage of D. melanogaster Exposed to Cd (VI). Real-time PCR and western blot analysis showed that SNP enhanced the gene expression of Diptericin, Drosomycin, Defensin, PGRP-LC and the protein level of Toll, p-JNK and Relish， that suggested the promoting effect of SNP on the immune damage repair of D. melanogaster exposed to Cd (VI). The increased level of Indy, Parkin and AMPK indicated the regulated effect of SNP on the longevity-related pathways through ageing-related moleculars of D. melanogaster exposed to Cd (VI). These results suggested that SNP could also improve the lifespan of D. melanogaster exposed to Cd (VI).     

电感耦合等离子体质谱（ICP-MS）法测定沙虫中10种重金属

建立了密闭高压消解-电感耦合等离子体质谱快速测定了沙虫中10种重金属元素(Pb、Tl、Cd、As、Cr、Ni、V、Cu、Sn、Sb)的方法，并分析了重金属的分布特征。试样经粉碎后，以HNO3和H2O2为消解剂进行消解处理，得到的消解液使用电感耦合等离子体质谱仪测定各元素的含量。结果表明，10种重金属元素元素的方法检出限在0.05～3.4μg/kg之间，相对标准偏差（RSD，n=3）小于4%，在0.05-100μg/L线性范围内线性关系良好，相关系数均大于0.999，方法用于国家有证标准物质（GBW10050）的测定，结果与标示值相符。方法灵敏度高，重现性好，定量准确，适用于沙虫样品的检测。