四肽Trp-Gly-Gly-His的合成及其对铜离子的检测

用固相合成法,将能特异性识别Cu2+的三肽Gly-Gly-His(GGH)与具有荧光发射功能的Trp(W)偶联,得到了由天然氨基酸组成的Cu2+分子探针Trp-Gly-Gly-His(WGGH)。该探针具有水溶性好,响应时间快、无毒安全、检测窗口宽、高灵敏度和高选择性等优点。实验优化得到的最佳检测pH为7.5。该探针对Cu2+的检测范围为10~1500 nM,检测限为2 nM。     

浅谈生物柴油在新疆发展

生物柴油即脂肪酸甲酯,可作为石油的代用品。主要利用动、植物油或油脚作为原料制成的一种环保型的、可再生的能源与工业原料。在新疆发展生物柴油除了有地域优势,在原料方面也有很大的优势。     

Effect of Heat Treatment Upon the Chemical Composition of Cottonseed Meal and Upon the Reactivity of Cottonseed Condensed Tannins

The effects of heat treatment on the chemical composition of cottonseed meal (CSM), with or without the addition of cottonseed hulls (containing condensed tannins; CT), and upon reactivity of the CT were studied. Heat was applied in a forced draught oven at 100°C for 2 h. Fluorodinitrobenzene (FDNB)-available lysine, free gossypol, extractable- and bound-CT concentrations, in vitro total nitrogen (N) solubility and the in vitro rumen degradation of the two major seed proteins (52 and 48 kDa) present in cottonseed kernel (which does not contain CT) were determined. The reactivity of CT was assessed by determining N solubility and rumen degradation of cottonseed kernel proteins in the presence or absence of polyethylene glycol (PEG; molecular weight (MW) 3500), which binds and inactivates CT. Heat treatment reduced the concentrations of free gossypol and FDNB-available lysine by small amounts, reduced measurable total CT content by 13%, reduced the solubility of total N, and reduced potential degradability of the 52 and 48 kDa cottonseed storage proteins by mixed rumen microorganisms. Addition of hulls further depressed solubility of total N and ruminal degradation of the two major storage proteins in cottonseed kernel. The action of PEG in vitro indicated that only part of the depression caused by hull addition could be explained by the presence of CT in the hulls, and that the effects of CT upon N solubility and potential degradability in heated CSM were similar to that in unheated CSM. Addition of hulls also substantially reduced FDNB-available lysine. In commercially produced materials, CSM from the Brisbane mill had a lower total CT content, lower N solubility and lower ruminal protein degradation rate than CSM from the Narrabri mill, but a similar level of FDNB-available lysine. Although application of heat inactivated 13% of the total CT, such that it could no longer be extracted and detected with butanol/HCl, it did not seem to change the overall effects produced by CT in reducing N solubility and protein degradation. The effect of hull addition in reducing available lysine has considerable relevance for feeding CSM to monogastric livestock. Interactions involving heat, hulls and CT need to be further studied.     

纳豆菌液态发酵制备蚕蛹肽的工艺优化及其抗炎活性研究

为提高蚕蛹的资源利用率和产品附加值,本研究以蚕蛹蛋白为原料,通过纳豆菌液态发酵制备蚕蛹肽.通过单因素实验和响应面试验确定最佳发酵工艺条件;采用脂多糖诱导RAW264.7巨噬细胞建立细胞炎症模型,对最佳发酵工艺参数组合下获得的蚕蛹肽进行体外抗炎活性研究.结果表明:蚕蛹肽的最佳发酵工艺条件为接种量5.0 mL、蚕蛹蛋白添加...     

胰蛋白酶酶解法制备海参肽的工艺条件

以海参肽得率为指标,分别考察了酶解加酶量、时间、pH、温度、底物浓度对胰蛋白酶酶解海参蛋白质反应的影响。通过正交实验确定了胰蛋白酶酶解海参蛋白的最佳工艺条件:酶加量6 000 U/g,水解反应时间3 h,温度55℃,pH 8.0,底物浓度1.0%,在此条件下,海参肽得率可达32.93%。     

英红九号茶蛋白ACE抑制肽的制备、氨基酸组成及不同超滤组分的活性评价

以英红九号红茶渣经碱溶酸沉提取的茶蛋白为研究对象,血管紧张素转化酶(ACE)抑制率为评价指标,通过单因素试验和响应面优化得到茶蛋白ACE抑制肽的最佳制备工艺,并对酶解物进行氨基酸组成分析、超滤膜分离和不同分子量组分的ACE抑制活性分析。结果表明,英红九号茶蛋白ACE抑制肽的最优酶解工艺为酶解温度37℃、3.20 h、p H值7.20、底物质量分数3%、酶底质量比0.40%,在此条件下进行的验证试验ACE抑制率为83.38%,与理论值84.48%较相符。英红九号茶蛋白ACE抑制肽酶解物富含必需氨基酸(33.03%)和对ACE抑制活性有重要意义的疏水性氨基酸(47.20%),且经超滤膜分离所得<3ku组分的ACE抑制活性(IC₅₀=0.85 mg/mL)要显著强于酶解物(IC₅₀=1.37 mg/mL)和>3 ku组分(IC₅₀=2.81 mg/mL)。该研究为食源性ACE抑制肽的研究开发和英红九号茶蛋白的高值化利用提供了理论依据。     

Relevance of AIF/CypA Lethal Pathway in SH-SY5Y Cells Treated with Staurosporine

The AIF/CypA complex exerts a lethal activity in several rodent models of acute brain injury. Upon formation, it translocates into the nucleus of cells receiving apoptotic stimuli, inducing chromatin condensation, DNA fragmentation, and cell death by a caspase-independent mechanism. Inhibition of this complex in a model of glutamate-induced cell death in HT-22 neuronal cells by an AIF peptide (AIF(370-394)) mimicking the binding site on CypA, restores cell survival and prevents brain injury in neonatal mice undergoing hypoxia-ischemia without apparent toxicity. Here, we explore the effects of the peptide on SH-SY5Y neuroblastoma cells stimulated with staurosporine (STS), a cellular model widely used to study Parkinson’s disease (PD). This will pave the way to understanding the role of the complex and the potential therapeutic efficacy of inhibitors in PD. We find that AIF(370-394) confers resistance to STS-induced apoptosis in SH-SY5Y cells similar to that observed with CypA silencing and that the peptide works on the AIF/CypA translocation pathway and not on caspases activation. These findings suggest that the AIF/CypA complex is a promising target for developing novel therapeutic strategies against PD.     

A Glutathione Peroxidase Gene from Litopenaeus vannamei Is Involved in Oxidative Stress Responses and Pathogen Infection Resistance

In shrimp, several glutathione peroxidase (GPX) genes have been cloned and functionally studied. Increasing evidence suggests the genes’ involvement in white spot syndrome virus (WSSV)- or Vibrio alginolyticus-infection resistance. In the present study, a novel GXP gene (LvGPX3) was cloned in Litopenaeus vannamei. Promoter of LvGPX3 was activated by NF-E2-related factor 2. Further study showed that LvGPX3 expression was evidently accelerated by oxidative stress or WSSV or V. alginolyticus infection. Consistently, downregulated expression of LvGPX3 increased the cumulative mortality of WSSV- or V. alginolyticus-infected shrimp. Similar results occurred in shrimp suffering from oxidative stress. Moreover, LvGPX3 was important for enhancing Antimicrobial peptide (AMP) gene expression in S2 cells with lipopolysaccharide treatment. Further, knockdown of LvGPX3 expression significantly suppressed expression of AMPs, such as Penaeidins 2a, Penaeidins 3a and anti-lipopolysaccharide factor 1 in shrimp. AMPs have been proven to be engaged in shrimp WSSV- or V. alginolyticus-infection resistance; it was inferred that LvGPX3 might enhance shrimp immune response under immune challenges, such as increasing expression of AMPs. The regulation mechanism remains to be further studied.     

海蜇低分子肽制备及体外抗氧化活性

目的 优化海蜇低分子肽(low molecular weight peptide from Rhopilema esculentum Kishinouye, RKLP)制备工艺,评价其抗氧化活性及分析氨基酸组成。方法 海蜇利用碱性和中性蛋白酶双酶分步酶解制备海蜇肽,以1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率为指标,响应面实验优化酶解工艺条件。采用超滤技术,获得分子量≤3.5 kDa RKLP。通过测定DPPH自由基、2,2’-联氮-双-3-乙基苯并噻唑啉-6-磺酸[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid),ABTS]自由基及超氧阴离子(O2-)自由基的清除率,评价RKLP抗氧化活性。氨基酸分析仪分析RKLP氨基酸组成。结果 酶解制备海蜇抗氧化肽的最佳工艺条件为:酶解温度50℃、3%碱性蛋白酶pH 7.5酶解2 h、1%中性蛋白酶pH 7.0酶解2 h,所得的DPPH自由基清除率为71.52%±0.59%,接近与预测值70.57%。RKLP水解度为6...     

聚(D,L-乳酸)基仿生聚合物材料的合成与表征

探索一种新型聚乳酸基仿生聚合物材料的制备新方法.具体实验步骤是:利用聚乳酸上叔碳原子的自由基反应活性,在过氧化二苯甲酰的催化作用下,将马来酸酐引入聚乳酸侧链上,以此提供高反应活性的酸酐键;然后利用酸酐基团与-NH2发生N-酰化反应这一特点,将脂肪族二胺引入聚乳酸侧链上,从而克服聚乳酸降解产物的体液环境呈酸性的缺陷;再用碳二亚胺作缩合剂,在二胺改性聚乳酸材料中共价引入一种细胞粘附肽段Arg-Gly-Asp-Ser(RGDS),赋予材料生物活性和生物特异性,这样就制备了一种新型聚乳酸基仿生材料.采用MALLS、FTIR和XPS对仿生材料进行结构表征;采用罗丹明比色法、茚三酮显色法和氨基酸分析仪检测法对仿生材料中的马来酸酐、二胺和粘附肽RGDS进行定量测定.结果表明,按文中所述之制备技术,在不改变聚乳酸材料主链结构的前提下,该仿生材料中粘附肽RGDS的含量是5.12μmol/g.这就形成了一种具有类似细胞外基质的新型仿生材料.