Lycium barbarum glycopeptide(wolfberry extract)slows N-methyl-N-nitrosourea-induced degradation of photoreceptors

Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photoreceptors in rd1, a transgenic mouse model of retinitis pigmentosa. L. barbarum glycopeptide(Lb GP) is an immunoreactive glycoprotein extracted from LBP. In this study, we investigated the potential protective effect of Lb GP on a chemically induced photoreceptor-degenerative mouse model. Wild-type mice received the following: oral administration of Lb GP as a protective pre-treatment on days 1–7;intraperitoneal administration of 40 mg/kg N-methylN-nitrosourea to induce photoreceptor injury on day 7;and continuation of orally administered Lb GP on days 8–14. Treatment with Lb GP increased photoreceptor survival and improved the structure of photoreceptors, retinal photoresponse, and visual behaviors of mice with photoreceptor degeneration. Lb GP was also found to partially inhibit the activation of microglia in N-methyl-N-nitrosourea-injured retinas and significantly decreased the expression of two pro-inflammatory cytokines. In conclusion, Lb GP effectively slowed the rate of photoreceptor degeneration in N-methyl-N-nitrosourea-injured mice, possibly through an anti-inflammatory mechanism, and has potential as a candidate drug for the clinical treatment of photoreceptor degeneration.

Retinal ischemia-reperfusion injury and pretreatment with Lycium barbarum glycopeptide

AIM:To investigate the antioxidant protective effect of Lycium barbarum glycopeptide(LbGP)pretreatment on retinal ischemia-reperfusion(I/R)injury(RIRI)in rats.METHODS:RIRI was induced in Sprague Dawley rats through anterior chamber perfusion,and pretreatment involved administering LbGP via gavage for 7d.After 24h of reperfusion,serum alanine aminotransferase(ALT),aspartate aminotransferase(AST),and creatinine(CREA)levels,retinal structure,expression of Caspase-3 and Caspase-8,superoxide dismutase(SOD)activity,and malondialdehyde(MDA)in the retina were measured.RESULTS:The pretreatment with LbGP effectively protected the retina and retinal tissue from edema and inflammation in the ganglion cell layer(GCL)and nerve fiber layer(NFL)of rats subjected to RIRI,as shown by light microscopy and optical coherence tomography(OCT).Serum AST was higher in the model group than in the blank group(P=0.042),but no difference was found in ALT,AST,and CREA across the LbGP groups and model group.Caspase-3 expression was higher in the model group than in the blank group(P=0.006),but no difference was found among LbGP groups and the model group.Caspase-8 expression was higher in the model group than in the blank group(P=0.000),and lower in the 400 mg/kg LbGP group than in the model group(P=0.016).SOD activity was lower in the model group than in the blank group(P=0.001),and the decrease was slower in the 400 mg/kg LbGP group than in the model group(P=0.003).MDA content was higher in the model group than in the blank group(P=0.001),and lower in the 400 mg/kg LbGP group than in the model group(P=0.016).The pretreatment with LbGP did not result in any observed liver or renal toxicity in the model.CONCLUSION:LbGP pretreatment exhibits dosedependent anti-inflammatory,and antioxidative effects by reducing Caspase-8 expression,preventing declines of SOD activity,and decreasing MDA content in the RIRI rat model.

Reversal of Apoptotic Resistance by Lycium barbarum Glycopeptide 3 in Aged T Cells

Objective To study whether Lycium barbarurn glycopeplide 3 （LBGP3） affects T cell apoptosis in aged mice. Methods LBGP3 was purified with DEAE cellulose and Sephadex columns. Apoptotic ＂sub-G1 peak＂ was detected by flow cytometry and DNA ladder was resolved by agarose gel electrophoresis. Levels of IFN-7 and IL-10 were measured with specific kits and mRNA expression was detected by RT-PCR. Apoptosis-related proteins of FLIP, FasL, and Bcl-2 were determined by Western blotting. Results LBGP3 was purified from Fructus Lycii water extracts and identified as a 41 kD glycopeptide. Treatment with 200 p.g/mL LBGP3 increased the apoptotic rate of T cells from aged mice and showed a similar DNA ladder pattern to that in young T cells. The reversal of apoptotic resistance was involved in down-regulating the expression of Bcl-2 and FLIP, and up-regulating the expression of FasL. Conclusion Lycium barbarum glycopeptide 3 reverses apoptotic resistance of aged T cells by modulating the expression of apoptosis-related molecules.

Experimental Study on the Enhancement of Murine Splenic Lymphocyte Proliferation by Lycium Barbarum Glycopeptide

In order to investigate the immunoactivity of Lycium Barbarum glycopeptide (LBG), the routinely prepared murine splenic lymphocyte suspension was separately added into the samples with different concentrations (500, 100, 10, 1 μg/ml) of LBG as LBG groups. Blank control group in the absence of Lycium Barbarum glycopeptide or ConA and positive control group in the presence of 0.5 ml ConA but in the absence of LBG were created. 0.5 ml LBG samples with different concentrations in combination with 0.5 ml ConA (10 μg/ml) into each well to observe the synergic effects of LBG and ConA as LBG+ConA groups. After incubation for 72 h at 37 ℃, the samples were analyzed by CFSE-labeled cells combined with flow cytometry, and MTT. Flow cytometry revealed that both LBG could enhance the murine splenic lymphocyte proliferative reaction. Combined use of LBG and ConA had synergic effects. MTT demonstrated that sample A could obviously promote the murine splenic lymphocyte proliferative reaction as compared with control group (P<0.01), while sample B could also enhance the lymphocyte proliferation at a high dose. In combination with ConA, sample A had synergic effects at high dose, while sample B showed obviously synergic effects (P<0.05). It was concluded that both samples (A and B) had strong immunocompetence.

Effects of laminin glycopeptides on metastasis-related behaviors of cancer cells

Our previous reports have shown that lamininglycopeptides (LN-GPs), the total glycopeptides prepared from laminin (LN), can prevent the experimental lung metastasis and liver metastasis of mouse cancer cells. In order to explore the anti-metastatic mechanism of LNGPs, we studied the effects of LN-GPs on metastasisrelated behaviors of cancer cells in vitro. LN-GPs did not affect cell survival. However, LN-GPs inhibited cell attachment and spreading Of 5180 cells on LN- and Matrigelsubstrate in dose-dependent and time-dependent manners. Moreover, inhibition of cen attachment and spreading on Matrigel substrates were much greater on Matrigel substrate than on LN substrate. In the presence of LN-GPs, 5180 cells on LN substrate changed from a flattened polygonal shape to a round one, the migration of 5180 cells on LN substrate decreased, and the number of a highly invasive human pulmonary giant caxcinoma PG cells invading Matrigel filter in a Boyden chamber was reduced. LN-GPs thus have multiple inhibitory effects on cancer motastasisrelated behaviors.

Effects of phosvitin phosphopeptide-Ca complex prepared by efficient enzymatic hydrolysis on calcium absorption and bone deposition of mice

Phosvitin(PV)was treated with high-temperature,mild pressure(HTMP),and enzyme combination,and then phosvitin phosphopeptides-calcium(PPP-Ca)complexes were prepared.The low-calcium specific pathogen free-Kunming(SPF-KM)mice were used to determine the effect of PPP-Ca complexes on intestinal calcium absorption and their utilization for bone formation.The serum calcium content was the highest with the HTMP-Enz-PPP-Ca treatment(2.19 mmol/L),and it significantly down-regulated the abnormal elevation of serum alkaline phosphatase(AKP)caused by calcium deficiency.The low-calcium control group had the lowest calcium deposited to the femur(80.41 mg/g)and the lowest femur bone mineral density(BMD)(0.17 g/cm^(3)),while HTMP-Enz-PPP-Ca significantly improved bone calcium content(94.33 mg/g)and BMD(0.29 g/cm^(3)).The micro-computed tomography(MCT)images showed that the femur with the normal control,PV-Ca,and HTMP-Enz-PPP-Ca treatments had a more compact,complete,and thicker trabecular network than the low-calcium and CaCl_(2)treatments.These results indicated that the organic calcium(HTMP-Enz-PPP-Ca)promoted calcium absorption and bone deposition,and the effect of HTMP-Enz-PPP-Ca was better than the inorganic CaCl_(2).

Enzymatic recovery of glycopeptides from different industrial grades edible bird’s nest and its by-products:nutrient,probiotic and antioxidant activities,and physicochemical characteristics

This study was conducted to recover edible bird’s nest(EBN)hydrolysates from different grades of EBN,including the industrial by-products,using enzymatic treatment.The nutrient,physicochemical properties and antioxidant activities of the recovered hydrolysates at different hydrolysis times were evaluated.Results showed that the recovery yield of enzymatic hydrolysis was above 89%for all grades of EBN and the degree of hydrolysis increased over time.Nitrite content(0.321-0.433 mg/L)was below the permissible tolerance level for all samples.Interestingly,the antioxidant activities(DPPH and ABTS scavenging activities and ferric reducing antioxidant powder(FRAP)activity)were significantly higher(P≤0.05)in hydrolysates recovered from EBN by-products(EBNhC and EBNhD)as compared to the high grade EBN hydrolysates(EBNhA and EBNhB).The in-vitro probiotic activity of EBN and its hydrolysates were examined using the probiotic bacterium Lactobacillus plantarum.Evidently,EBN by-products hydrolysate(EBNhD)recorded the highest number of L.plantarum(1.1×1011 CFU/mL),indicating that low grade EBN has the potential as prebiotic material that promotes probiotic activity.This study demonstrated the concept of using EBN by-products hydrolysates for various applications,such as functional ingredients with enhanced bioactivities,to improve its economic value.

Structural Analysis of an Oligosaccharide and Glycopeptide Mixture from Panax Ginseng Root with Inhibition SHP-1 Function

A mixture of oligosaccharide and glycopeptide was isolated from the aqueous extract of Panax ginseng roots. The mixture inhibits protein tyrosinc phosphatase（SHP-1） function, implying it enhances immune activity. The peak molecular mass of the oligosaccharide portion is 1800 calculated via GPC software after separation by HPLC. And the structure of the oligosaccharide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→4）- and （1→6）-linked glucopyranoside, with non-reducing terminals of arabinopyranoside and glucopyranoside. The peak molecular mass of glycopeptide portion is 1900 calculated via GPC software after separation by HPLC. The structure of glycopeptide portion is the backbone of （1→3）- and （1→4）-linked arabinopyranoside, and （1→3,6）-linked glucopyranoside, with non-reducing terminals of galactopyranose and glucopyranoside. The peptide composition is Glu. Asp, Hyp, Set, Arg, Gly , Thr, Pro, Ala, Val, lie, Leu and Lys. The oligosaccharide-peptide linkage is formed by Ara and Hyp.

Online Effective Identification of Glycopeptide Using Liquid Chromatography Combined with Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FTICR-MS)

The detailed glycan structural analysis of glycoprotein is amenable to glycopeptide enrichment. Here, we develop a simple, effective and economical approach to enrich glycopeptides from proteolytically digested peptide mixtures by chromatographic column packed with graphite carbon and activated charcoal (G/A-column). Glycopeptide from ovalbumin was efficiently enriched by homemade G/A-column using liquid chromatography and the structure of glycopeptide was obtained by tandem mass spectrometry using Fourier transform ion cyclotron resonance mass spectrometry. The results in this study demonstrate that G/A-column can be used to enrich N-glycolpeptides and be benefit for online identification of glycopeptide using LC-MS.

Optimized extraction and purification technology of Gekko sulfated glycopeptide based on its anticancer activities

Objective:To optimize the extraction and purification technologies of Gekko sulfated glycopeptide based on the content of glycopeptide,removal ratio of proteins,and anticancer activities.Methods:Different extraction methods,namely,water extraction,ultrasonic extraction,enzymatic hydrolysis-water extraction,and enzymatic hydrolysis-ultrasonic extraction were considered to determine the best extraction method.Single factor and orthogonal experiments were performed to determine the optimum extracting conditions.Sevage,enzymatic hydrolysis-Sevage,trichloroacetic acid(TCA),TCA-Sevage and enzymatic hydrolysis-TCA methods were tested to determine the best deproteinization method.The glycopeptide content and protein removal ratio were analyzed by the phenol-sulfuric acid and Coomassie Brilliant Blue methods.Results:Gekko sulfated glycopeptide obtained by water extraction could inhibit the proliferation of HepG2 and SKBR3,as well as promote that of lymphocytes.The glycopeptide content was 4.049%in the optimal extracting condition of a triple decoction extraction for 1 hour each time with a material to solvent ratio of 1:15.The enzymatic hydrolysis-TCA method was found to be the optimal deproteinization method,with a protein removal ratio of 50.46%,glycopeptide content of 14.27%,and inhibitory ratio on human HepG2 cells of 49.06%.Conclusion:This extraction and purification technique for Gekko sulfated glycopeptide is reasonable,feasible,and provides a scientific basis for industrial production.

The effects of Gekko sulfated glycopeptide and basic fibroblast growth factor on human fibrosarcoma HT1080 cells

Background:Fibrosarcoma is a malignant soft tissue tumor of mesenchymal origin.Gekko sulfated glycopeptide(GSPP),an anticancer drug in traditional Chinese medicine,could inhibited the tumor angiogenesis by targeting basic fibroblast growth factor(bFGF).bFGF promoted the proliferation of fibroblasts.Both fibrosarcoma and fibroblasts derived from fibrous connective tissue.This study investigated whether GSPP has the inhibitory effects on human fibrosarcoma HT1080 cells.Materials and methods:The trypan blue exclusion assay was used to determine cell viability and cell numbers.Cells migration was observed by wound-healing and transwell.Results:From the first day to seventh day,HT1080 cells number of GSPP,bFGF,GSPP combined bFGF groups had not change compared with control.HT1080 cells migration distance and the number of migrating cells of GSPP,bFGF,GSPP combined bFGF groups were not significantly reduced.Conclusions:GSPP did not have inhibitory effects on the proliferation and migration of human fibrosarcoma HT1080 cells.Thus further research should be carried out in order to study the mechanism of GSPP and bFGF acting on the tumor stroma.

Biomechanics mechanism of the anti-tumor effects of sulfated polysaccharide and sulfated glycopeptide

There are also a variety of cytokines in the tumor microenvironment,which are involved in the change in the hardness of the tumor,thereby affecting the invasion and metastasis of tumor cells.As traditional Chinese medicines,drugs of softening and dissipating firm knot contains different kinds of sulfated polysaccharide and sulfated glycopeptide.By inhibiting the function of cancer-associated fibroblasts,they reduce interstitial fibrosis,thereby reducing the hardness of the tumor and exerting an anti-tumor effect.

Different Regulation Effects of Gekko Sulfated Glycopeptide in Breast and Liver Cancer Cell Lines

Background:Our previous work demonstrated that Gekko sulfated glycopeptide extracted from the Chinese gecko Shou gong(Gekko swinhonis Guenther)could inhibit tumor growth by regulating basic fibroblast growth factor.However,basic fibroblast growth factor has opposing effects on growth in breast and liver cancers.Direct effects and mechanisms of Gekko sulfated glycopeptide on tumor growth remain unclear and are ripe for further exploration.Methods:Differential regulation by Gekko sulfated glycopeptide and bFGF were studied in established human breast cancer MCF-7 cells and hepatocarcinoma HepG2 cells.Cell proliferation was evaluated with a Trypan blue exclusion assay.Cell cycle phases were measured by flow cytometry.Basic fibroblast growth factor,transforming growth factor-β1,and p21WAF1/CIP1 mRNA and protein expression levels were detected by real-time PCR(mRNA)and ELISA(protein).Changes in phosphorylated extracellular signal-regulated kinase levels were analyzed by Western blot.Results:Data indicated that Gekko sulfated glycopeptide inhibited the proliferation of HepG2 cells(P<0.001)and also blocked basic fibroblast growth factor-stimulated proliferation of these cells(P=0.001).Gekko sulfated glycopeptide was shown to increase transforming growth factor-β1 and p21WAF1/CiP1 expression(P<0.01)and partially compensate for reductions therein induced by basic fibroblast growth factor.Conversely,in MCF-7 cells,Gekko sulfated glycopeptide alone had no observable effect on transforming growth factor-β1 and p21WAF1/CiP1 expression.Gekko sulfated glycopeptide did,however,enhance basic fibroblast growth factor-induced inhibition of cell proliferation and transforming growth factor-β1 and p21WAF1/CiP1 expression in the MCF-7 cells(P=0.001,P<0.01,P<0.01,respectively).Gekko sulfated glycopeptide was shown to suppress basic fibroblast growth factor secretion in both HepG2 and MCF-7 cell lines(P<0.05 and P<0.01,respectively)and inhibited extracellular signal-regulated kinase 1/2 phosphorylation facilitated by basic fibroblast growth factor.Gekko sulfated glycopeptide alone decreased phosphorylated extracellular signal-regulated kinase in HepG2 cells but did not visibly affect phosphorylated extracellular signal-regulated kinase levels in MCF-7 cells.Conclusions:Gekko sulfated glycopeptide,a basic fibroblast growth factor inhibitor,differentially regulates growth in different cancer cell lines,and these differences may be determined by the opposing effects of basic fibroblast growth factor on transforming growth factor-β1 and p21WAF1/CiP1 levels in breast and liver cancer cells.

仿生再矿化治疗在牙釉质早期脱矿的作用及机制

背景:随着饮食改善和生活水平提高,酸性饮食和正畸治疗等成为导致牙釉质表面脱矿的主要原因。作为牙齿龋坏的第一步,牙釉质脱矿应被积极干预,机械磨除损伤较大且不符合微创医学理念,仿生再矿化是目前应对牙釉质脱矿的最佳方式。目的:通过对牙釉质早期脱矿的仿生再矿化治疗机制、应用方式及研究进展进行综述,为进一步攻克仿生再矿化热点难题提供思路。方法:以“Enamel demineralization,Biomimetic remineralization,amelogenin,Amorphous calcium phosphate”等作为英文关键词在PubMed数据库检索,以“釉质脱矿,仿生再矿化,釉原蛋白”等关键词在中国知网数据库进行检索,通过筛选最终共得到72篇文献进行综述分析。结果与结论:①目前针对釉质脱矿有药物治疗如含氟制剂等、激光治疗、树脂渗透、再矿化治疗等治疗方式,仿生再矿化是目前牙釉质早期脱矿最理想的修复方式。②狭义的釉质再矿化指早期釉质脱矿后内部的矿物质再沉积,广义的釉质再矿化包括釉质表面和内部两方面的矿化沉积。③临床仿生再矿化试剂多以釉原蛋白、非釉原蛋白、釉原蛋白肽、酪蛋白磷酸肽-不定形磷酸钙复合物等为主要成分。蛋白及肽类材料优势在于符合生理机制,可通过诱导定向生成高强度再矿化材料,劣势在于制作工艺相对复杂,成本较高;不定形磷酸钙复合物再矿化效果好,但需与其他材料结合使用以发挥作用;其他磷酸钙材料便于携带、有利美观,但易导致牙石形成。④未来研究应着重于以下几个方面:增加随机对照试验数据和临床结果,明确各个方式的适应证;发掘更多仿生再矿化方法,寻找合适替代材料;寻找合理的材料结合方式,以使其优缺点互补;加强临床应用便携性,以增加日常使用频率,使短期实验结论获得长期临床数据支持。

Inherently hydrophilic mesoporous channel coupled with metal oxide for fishing endogenous salivary glycopeptides and phosphopeptides

Both glycosylation and phosphorylation exert crucial rule in multitudinous biological processes.For in-depth profiling of glycosylation and phosphorylation,a magnetic metal oxide is effectively coupled with inherently hydrophilic mesoporous channels(denoted as Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG).Based on the mechanism of hydrophilic interaction liquid chromatography(HILIC)and metal oxide affinity chromatography(MOAC),the Fe_(3)O_(4)@TiO_(2)@mSiO_(2)-TSG nanomaterial shows high capacity for simultaneously enriching glycopeptides and phosphopeptides.With human saliva collected in successive four days as practical biological sample,endogenous glycopeptides and phosphopeptides are efficiently enriched.Further gene ontology analysis reveals that the identified endogenous glycopeptides and phosphopeptides participate in diverse molecular functions and biological processes.This strategy is anticipated to promote variation analysis of salivary post-translational modifications.

玉米糖肽抗氧化活性的稳定性研究

为研究玉米糖肽在食品加工条件下抗氧化活性的稳定性,以转谷氨酰胺酶(TGase)为催化剂,利用生物安全、多伯氨基团的壳寡糖(COS)对玉米醇溶蛋白源活性肽进行糖基化修饰制备玉米糖肽,以DPPH自由基清除率和亚铁离子螯合率为指标,探究冻融次数、温度、pH、食品辅料(NaCl、葡萄糖和柠檬酸)和体外模拟胃肠消化对玉米糖肽抗氧化活性的影响。结果表明,玉米糖肽具有良好的冻融稳定性(4次)和热稳定性(60~100℃),弱碱(pH 8.0)条件下稳定,NaCl(0.5~5.0 g/100 mL)的添加对玉米糖肽的抗氧化活性无显著影响,葡萄糖(1~8 g/100 mL)的添加对DPPH自由基清除活性无显著影响,对亚铁离子螯合能力有促进作用,柠檬酸(0.04~0.20 g/100 mL)的添加及体外模拟胃肠消化对DPPH自由基清除活性有促进作用,对亚铁离子螯合能力有抑制作用。因此玉米糖肽具有一定的抗氧化活性稳定性,选择合理的加工及储藏条件有利于维持玉米糖肽的抗氧化活性。

磁性氮化碳复合材料的制备及其对磷酸化肽的富集

蛋白质的磷酸化在细胞信号传导和疾病发生发展中起着重要作用,但磷酸化的动态变化和低丰度的特点使得对其直接分析有着较大的困难。为了解决磷酸化肽难离子化、检测丰度低的瓶颈问题,本研究制备了一种磁性氮化碳复合材料,结合基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS),建立了一种对复杂样品中低丰度磷酸化肽富集与分析的方法。采用电子显微镜、红外光谱分析及X射线衍射分析等手段对合成的磁性氮化碳材料进行表征。以酪蛋白酶解产物为实验模型,发现磁性氮化碳材料能够实现对磷酸化肽的高选择性富集和高灵敏度检测,检出限为0.1 fmol。选择脱脂牛奶、人唾液和人血清为实际分析样品,发现磁性氮化碳材料对微量蛋白生物样品中磷酸化肽的分析具有较高的应用潜力。

酪蛋白磷酸肽-钙螯合物的分级、表征及持钙特性

利用酪蛋白磷酸肽螯合钙离子的特性,以钙离子浓度为尺度,分级制取不同钙螯合能力的CPPs,同时提高其纯度。以酪蛋白的胰蛋白酶酶解产物为原料,通过逐级增加Ca^(2+)添加量,在终浓度为55%(v/v)的乙醇溶液中分级沉淀出三个酪蛋白磷酸肽-钙螯合物级分(CPP1-Ca、CPP2-Ca和CPP3-Ca),并利用PBS脱钙得到三个级分相应的酪蛋白磷酸肽(CPP1、CPP2和CPP3)。以传统钙乙醇沉淀法得到的肽钙螯合物(CPP-Ca)为对照,分析并对比三个酪蛋白磷酸肽-钙螯合物级分的理化性质以及持钙特性。结果表明,三个酪蛋白磷酸肽-钙螯合物级分中,CPP3-Ca含有最高的纯度和钙螯合量,分别为89.42%和69.59 mg/g,明显高于未分级CPP-Ca的83.77%和55.05 mg/g。氨基酸组成及N/P(摩尔比)分析发现CPP3-Ca含有更高磷酸丝氨酸基团,进而能够结合更多的Ca^(2+)。不同酪蛋白磷酸肽级分持钙能力分析结果显示CPP3能够更好地延迟和阻止磷酸钙沉淀的形成,具有更高的持钙能力。同时CPP3-Ca在模拟肠道环境中具有更高的钙溶解度,表明分级后的酪蛋白磷酸肽-钙螯合物的体外生物利用度提高。

荞麦糖肽脂质体的制备及其稳定性和缓释研究

制备一种荞麦糖肽(buckwheat glycopeptide,BG)缓释脂质体,提高荞麦糖肽的生物利用度。本研究首先对制备所得的BG进行稳定性分析,随后利用反向蒸发法制备荞麦糖肽脂质体(buckwheat glycopeptide liposomes,BGL),经响应面实验对包埋工艺进行优化,并探究其稳定性、体外缓释特性、α-葡萄糖苷酶(α-glucosidase,AGase)抑制活性和抗氧化活性。结果表明:温度(20~80℃)对BG的活性影响较小,碱性条件下BG易失活。从5种磷脂中筛选出蛋黄卵磷脂制备BGL,响应面优化工艺条件为磷脂与胆固醇质量比为4.2∶1.0,脂药比为7.5∶1.0,水相体积为1 mL,此条件下,BGL包埋率为72.64%。BGL对高温(100℃)环境不耐受,在短时间(1 h)内具有广谱pH(2~10)稳定性,反复冻融5次对其渗漏率无显著影响(P>0.05)。BGL在体外模拟胃、肠体系中表现出良好的缓释特性,24 h累计释放速率分别为(84.50±2.30)%和(60.17±1.42)%。

磷酸化肽段分离富集方法的研究进展

目的:通过综述O-磷酸化肽段和N-磷酸化肽段的富集方法研究进展,为磷酸化蛋白质分析前处理提供解决方案。方法:结合文献和数据库搜索,总结O-磷酸化肽段和N-磷酸化肽段的富集方法基本原理与应用,系统介绍O-磷酸化肽段和N-磷酸化肽段的富集方法研究进展。结果:磷酸化肽段分离富集方法已被广泛应用于磷酸化蛋白质组学研究中。结论:目前已开发了多种针对不同磷酸化肽段的富集方法,不同的方法具有不同的特异性和选择性,因此,根据研究目的选择富集方法尤为重要。