Alcalase酶解芝麻蛋白制备ACE抑制肽的工艺研究

以芝麻蛋白为原料,采用酶解法制备血管紧张素转化酶(Angiotensin I-Converting Enzyme,ACE)抑制肽。通过比较Alcalase酶、碱性蛋白酶2709、胰蛋白酶、菠萝蛋白酶和中性蛋白酶的酶解结果,筛选出Alcalase酶作为制备ACE抑制肽的工具酶。通过单因素试验,分析了时间、p H、加酶量、温度及底物浓度对短肽生成率和水解度的影响。基于单因素试验结果,固定加酶量为3 000 u/g和底物浓度为3%,以短肽生成率和ACE抑制率为考察指标,通过响应面优化试验确定Alcalase的最佳水解条件为:时间147 min,p H 8.24,温度55℃。在此条件下短肽生成率和ACE抑制率分别为75.27%和70.80%,IC50值为1.004 mg/m L。     

用2709碱性蛋白酶水解醇洗花生蛋白制备血管紧张素转化酶(ACE)抑制肽

采用2709碱性蛋白酶水解醇洗花生蛋白制备ACE抑制肽。以短肽得率、水解度和ACE抑制率为指标,通过单因素和响应面优化设计获得最佳酶解工艺条件:p H 9.3、酶解温度50℃、时间150 min、加酶量3 000 U/g和底物浓度4%,在最佳酶解条件下,短肽得率为77.89%,水解度为17.87%,ACE抑制率为76.26%。结果表明:适当的酶解时间和温度能提高短肽得率和ACE抑制率,但酶解时间过长,过度水解会使短肽失去ACE抑制结构,降低ACE抑制率。     

酶法制取鱼皮胶原蛋白短肽

采用高效、环保的水解方法提取了鳕鱼皮中的胶原蛋白,并应用木瓜蛋白酶制取鱼皮胶原蛋白短肽,根据胶原蛋白的提取率确定了提取的最适反应条件,通过纸层析和SDS-PAGE电泳技术分析了鱼皮胶原蛋白的水解情况。结果表明,酶与原料比为1∶300、酶反应时间10 h、反应温度55℃、pH值为6.8,胶原蛋白的提取率最高;鱼皮胶原蛋白的水解产物主要以6~29 ku的小分子质量的短肽形式存在。以废弃鳕鱼皮作实验材料,可减少环境污染,节约资源,提高水产品废弃物的附加值。     

酶法制取鱼皮胶原蛋白短肽

采用高效、环保的水解方法提取了鳕鱼皮中的胶原蛋白,并应用木瓜蛋白酶制取鱼皮胶原蛋白短肽,根据胶原蛋白的提取率确定了提取的最适反应条件,通过纸层析和SDS-PAGE电泳技术分析了鱼皮胶原蛋白的水解情况。结果表明,酶与原料比为1∶300、酶反应时间10 h、反应温度55℃、pH值为6.8,胶原蛋白的提取率最高;鱼皮胶原蛋白的水解产物主要以6~29 ku的小分子质量的短肽形式存在。以废弃鳕鱼皮作实验材料,可减少环境污染,节约资源,提高水产品废弃物的附加值。     

二剂量法测定乳链菌肽效价及其C++运算程序

准确测定乳链茵肽效价是发酵法工业化生产乳链茵肽很重要的环节．效价检测过程中影响因素很多，其中标准品和样品所产生差异的一些因素对测定有很大的影响．本文利用二剂量法检测乳链茵肽效价，检测过程中只需研究样品溶液和标准品溶液对检测造成的影响，排除了其它影响因素：确定了效价计算的C 运算程序，避免了通过标准曲线法计算效价产生的误差．大幅度提高了测定乳链茵肽效价的准确性。     

响应面法优化采油菌株Bacillus FH-1-2产脂肽发酵培养基

运用Plackett-Burman法确定了影响脂肽产量的3个重要因素:FeSO4、MnSO4和酵母粉,通过最陡爬坡试验确定了以上3个重要影响因素的最佳质量浓度范围,再利用Box-Behnken设计得出回归方程并利用Minitab软件进行回归分析,得到各因素的最佳质量浓度(g/L):FeSO40.011,MnSO40.204,酵母粉0.205,KH2PO43.4,Na2HPO41.5,NaNO34,MgSO4.7H2O 0.2,液体石蜡25。采用优化后的培养基进行发酵,发酵液的表面张力值降至38.4 mN/m,脂肽产量达到401 mg/L,提高了19.7%。     

阿片生物活性肽的基因设计、化学合成及克隆

在阿片类生物活性短肽的结构和生理特点基础之上，通过重复叠加的方法设计了此类生物活性肽基因．借助Primer软件，设计了3条引物；并通过引物延伸和PCR等步骤，实现了基因的人工合成并克隆至表达载体pPIC9K．PCR及酶切鉴定后测序，表明所合成基因已成功克隆。     

牡蛎功能短肽的制备及ACE抑制活性

以新鲜无壳牡蛎为原料，采用酶水解的方法制备牡蛎短肽，经Sephadex G-15分离，并用HPLC测定其相对分子质量分布，通过HPLC法定量马尿酸测定各组分的ACE(血管紧张素转化酶)抑制活性。结果表明，牡蛎水解液中相对分子质量较大和较小部分的ACE抑制活性偏低，只有相对分子质量在一定范围内的短肽，对ACE具有较好的抑制作用，质量浓度为0．4mg／mL的牡蛎功能短肽的ACE抑制率为51．4％．     

丝素肽在化妆品中的应用研究

丝素溶于强极性的浓盐溶液中,经透析、水解后生成丝素肽.对丝素肽的理化性能研究表明,其分子量3000～6000,分子构象为无规卷曲结构,可溶于水.丝素肽含有十多种氨基酸,极易被皮肤所吸收,它是皮肤的天然调湿因子,同时能抑制皮肤中黑色素的生成.用电镜观察丝素肽涂抹头发表面,干燥后在其表面形成结晶性的保护膜.丝素肽是一种崭新的化妆品添加剂.     

HLA-A*0201限制性CTL表位肽分子力场分析

运用比较相似性指数分析(CoMISA)方法研究了203个HLA-A*0201限制性CTL表位九肽结构与亲和性间的关系,另外30个表位九肽作为预测集用于检验模型的预测能力.得到构效关系模型结果q2=0.548,r2=0.963,F=553.4,SD=0.154.在CoMSIA计算中,当引入疏水场时,三维构效关系模型能得到明显改善.通过该三维构效关系模型,可较精确地估算预测集中30个CTL表位肽与HLA-A*0201间的亲和力(r2pred=0.532,SD=0.454).通过分析分子场等值面图在空间的分布,可以观察到表位肽分子周围的立体及疏水特征对表位肽H与A-A*0201间结合亲和力的影响,从而为进一步对CTL表位肽进行结构改造,并基于此进行治疗性疫苗分子设计提供理论基础.     

PET膜的接枝改性及其血液相容性研究

对PET(聚对苯二甲酸乙二醇酯)材料进行表面改性,以提高材料表面亲水性和抗凝血性能,采取紫外共辐照方法和逐步偶合接枝方法,先在PET表面接枝聚乙二醇,然后通过化学偶合方法在聚乙二醇末端接枝抗凝血药物肝素。改性后PET材料的表面亲水性和抗凝血性能得到很大改善。PET表面亲水性随着接枝PEG的分子量和反应浓度的增大而增强。使用亲水性高聚物PEG作为空间臂,可以很好地保持肝素的生物活性。通过紫外改性成功地在材料表面接枝了PEG和肝素,很好地改善了材料的生物相容性。     

Preparation of immobilized <Emphasis Type="Italic">ɛ</Emphasis>-polylysine PET nonwoven fabrics and antibacterial activity evaluation

A novel antibacterial material (L-PET) was prepared by immobilizing ε-polylysine on polyethylene terephthalate (PET) nonwoven fabrics. Surface modifications of the fabric were performed by using a chemical modification procedure where carboxyl groups were prepared on the PET surface, a coupling agent was grafted, and the ε-polylysine was immobilized. Scanning electron microscopy (SEM) was used to analyze the surface morphology of the fabrics, while the toluidine blue method and X-ray photoelectron spectroscopy (XPS) were used to evaluate the grafting densities. The antibacterial activities of the L-PET were investigated by using the shaking-flask method. The electron micrographs showed that the surface of the blank PET and the modified fabrics did not change. The results of XPS analysis confirmed that ε-polylysine was successfully grafted onto the surface of PET. The results of the antibacterial experiments showed that L-PET fabrics had excellent antibacterial activity against Escherichia coli and Staphylococcus aureus, and that L-PET fabrics were stable in storage for at least two years.     

涤纶表面TiO2薄膜的制备及抗紫外线性能研究

通过磁控溅射将二氧化钛（TiO₂）沉积在涤纶织物表面形成薄膜,制备二氧化钛/涤纶（TiO₂/PET）抗紫外线功能织物,探讨制备过程中磁控溅射时间和溅射功率对织物抗紫外线功能的影响,分析TiO₂薄膜的紫外线吸收和屏蔽机理,同时检测织物隔热、热稳定性能的变化情况. 结果表明:在PET织物表面沉积TiO₂薄膜可改善织物的抗紫外线性能,归因于TiO₂薄膜对紫外光较好的吸收和对紫外可见光有效的屏蔽能力;且因TiO₂薄膜在溅射150 W以上的功率下粗糙度增加、厚度减少,当溅射功率为150 W,溅射时间为90 min时,TiO₂/PET织物具有较强的抗紫外线能力,其紫外线防护系数（Ultraviolet Protection Factor,UPF）达到1211.19;同时,TiO₂薄膜的沉积赋予了PET织物良好的热稳定性能和隔热性能.     

Immobilization of RGD peptide onto the surface of apatite-wollastonite ceramic for enhanced osteoblast adhesion and bone regeneration

The arginine-glycine-aspartic （RGD） acid peptide was grafted to the surface of apatitewollastonite （AW） ceramic in an effort to improve its cell adhesion, proliferation and osteoinduction. RGD peptide was covalently immobilized onto the surface of AW ceramic via the synthetic cross linker AA.PTS-E and 1-ethyl-3-（3-dimethylaminopropyl）carbodiimide （EDC）. The modified surfaces were characterized by attenuated total reflectance Fourier transform infrared spectroscopy （ATR-FTIR） and X-ray photoelectron spectroscopy （XPS）. The chemical analysis indicated that RGD peptide had been immobilized onto the AW surface successfully. The growth of osteoblast-like cells （MG63） showed that modifying the AW surface with RGD peptide enhanced the cell adhesion and proliferation. And the histological evaluation of RGD-AW showed that the bone regeneration and remodeling process were significantly enhanced compared to the original AW ceramics after 2, 4 and 8 weeks implantation in rabbit＇s femoral condyles.     

油膜润滑条件下滑动轴承变形与应力数值模拟

针对某汽轮发电机组转子的动压滑动轴承,采用热流耦合方法求解轴瓦及油膜的温度场,应用有限差分法对雷诺方程求解得到开设油槽条件下的油膜压力分布,提出一种离散化的油膜压力载荷与轴瓦内孔表面网格的批量映射匹配方法.在获得能够保证轴承正常工作的合理油膜温度场之后,对轴瓦进行热固耦合求解,得到轴瓦的变形和应力分布.通过分别对不同宽径比与偏心率下轴瓦变形与应力的数值模拟结果比较,得到轴瓦变形及应力分别随宽径比和偏心率的变化规律.结果表明,该方法能够有效地完成动压滑动轴承变形和应力的数值模拟,轴承轴瓦的变形及应力均分别随宽径比和偏心率的增大而增大．     

Influence of different substrates on the electrochromic property of polyaniline films

The polyaniline (PANI) films doped with complex acid (sulfuric acid and sulfosalicylic acid) were prepared using the potentiostatic method on bare nickel flake (NF) and flexible polyethylene terephthalate (PET)/indium tin oxide (ITO) substrates. The contents of the PANI films, surface elements, electrochromic property and electrical conductivity were characterized by energy dispersive X-ray spectrometer (EDS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results show that differences exist among cycle stability, redox reversibility and response time of polyaniline films on these two kinds of substrates, but the electrochromic phenomenon of the PANI films is in substantial agreement. The equilibrium transmittance spectra in the visible region (400–800 nm) for the PANI film on flexible PET/ITO substrate was obtained at different applied potential from −0.4 to 1.5 V. The results show that the transmittance of the PANI film by applying voltage is adjustable in a row and has excellent electrochromic performance.     

基材清洗工艺对SiO2/PET膜基结合强度的影响

采用磁控溅射工艺,在PET表面沉积Si O2薄膜,利用SEM观察镀膜的表面形貌,通过附着力测试仪检测Si O2/PET膜基的结合强度,研究基材PET表面清洗工艺对Si O2/PET膜基结合强度的影响。结果表明:结合强度因PET基材表面清洗工艺的不同而不同,其中经等离子清洗的膜基结合强度最大,达0.14MPa,分别较深度清洗、一般清洗和不清洗的膜基结合强度高7.83%,27.27%,55.56%;等离子清洗工艺参数对膜基结合强度有较大影响,随着清洗时间的增加、氩气流量的增大和清洗功率的提高,膜基的结合强度均呈现出先增大后减小的变化趋势。     

无纺布负载锰氧化物的制备及其催化分解甲醛性能研究

随着物质生活的不断提高,甲醛成为了室内空气污染的主要物质,对于室内空气净化过程,去除甲醛技术变得尤为重要. 利用条件温和、过程简单的水浴法使二氧化锰（MnO₂）原位负载到聚对苯二甲酸乙二醇酯（PET）制成的无纺织物上,制备出MnO₂/PET整体式催化剂. 合成的MnO₂/PET复合物通过扫描电子显微镜（SEM）、X射线衍射（XRD）、比表面积测试（BET）进行表征分析,并在手套箱中模仿室内环境进行甲醛去除测试以及催化剂寿命测试. 结果表明：整体式催化剂中的锰氧化物为水钠锰矿型二氧化锰,并均匀、牢固负载在无纺布上. 由于其有较大的比表面积,在甲醛去除能力方面展示出了优良的性能,在甲醛初始质量浓度为2.84 mg/m³的氛围测试中经过6 h,最后使甲醛质量浓度降低至0.33 mg/m³,甲醛去除率达到88.29%. 提供了一种高效的去除甲醛的催化剂合成方法,这种整体式催化剂为室内甲醛催化净化拓展了新的思路.     

Adsorption of K+ from an aqueous phase onto an activated carbon used as an electric double-layer capacitor electrode

The adsorption capacity and absorption rate for electrolyte onto activated carbon are important parameters used to characterize activated carbon electric double-layer capacitor electrodes. In this paper the pore structure of typical commercial activated carbons, and various Mn-doped activated carbons prepared on a laboratory scale, are described. The pore structure was characterized by N2 adsorption/desorption isotherms. Isotherms for K+ adsorption onto these activated carbons from the aqueous phase were also obtained. The experimental, equilibrium K+ adsorption data were fitted to the Langmuir, Freundlich or Temkin equations. Adsorption of K+ onto the activated carbons was measured and plotted as a function of time. The adsorption kinetic data were modeled by either pseudo-first or pseudo-second order equations. The Elvoich equation, a liquid film diffusion and an intra-particle diffusion model were used to fit the kinetic data. The results indicate that the adsorption of K+ onto activated carbon is influenced by many factors including pore size distribution, specific surface area and the surface chemistry of the activated carbons. The Temkin equation best describes the equilibrium adsorption data. The pseudo-second order model exactly describes the whole adsorption process, which is controlled by both liquid film and intra-particle diffusion.     

磁控溅射法制备防水透湿织物初探

利用自制磁控溅射设备在PET织物上以聚四氟乙烯为靶材,制备了防水透湿织物。溅射后PET织物的抗湿性明显提高,透湿性几乎没有改变,接触角显著增大,说明此种方法制备防水透湿织物是可行的。溅射后织物表面生成一种不同于聚氟乙烯和聚四氟乙烯结构的薄膜,薄膜呈多层贯通蜂窝状结构