高效凝胶过滤色谱法测定肽的相对分子量分布

采用高效凝胶过滤色谱法,对肽粉、酵母核苷酸和自溶酵母粉三种肽类产品的相对分子量大小及分布进行了测定。结果表明,此三种产品的相对分子量分布范围集中在2000Da以下,寡肽含量丰富,其中含有一定量的游离氨基酸和氨基酸残基。该方法简便快捷、准确性高、重复性好,适合肽类产品分子量(<1 0KD)分布的分析检测。     

白及/魔芋复合凝胶体系的构建及性能表征

以白及/魔芋为基质,采用冻融法构建了一种具有抑菌功效的复合凝胶体系。通过单因素试验优化了白及/魔芋复合凝胶体系的制备工艺,利用红外光谱仪、X-射线衍射仪和扫描电子显微镜等对复合凝胶的结构及性能进行了表征,并考察了复合凝胶对大肠埃希氏菌和金黄色葡萄糖菌的抑菌效果。结果表明,当白及与魔芋质量比为3∶1,氢氧化钠浓度2 mg/g,凝胶温度70℃时,制备的复合凝胶性能较好,结构完整,孔隙均匀,吸水率高达1465.4%,透气量为114000.246 g/(m³·h),最大应力为0.68 MPa,抑菌效果明显。白及/魔芋复合凝胶可作为一种具有潜在应用价值的新型抑菌敷料。     

苹果叶片总蛋白提取及其双向电泳分析

蛋白质提取方法和电泳条件的建立是蛋白质组学研究中双向电泳分析的关键。通过比较不同提取方法,包括酚/SDS抽提、TCA-丙酮沉淀法、甲醇/醋酸铵沉淀法以及改良HB-酚抽提方法。此外,还优化了样品上样量、等电聚焦程序设置等条件。从所得2-D图谱分离效果来看,改良HB-酚抽提方法所得蛋白点数最多,2-D图谱背景清晰、分离效果好,明显优于其他3种方法。300μg上样量可作为苹果叶片总蛋白2-DE分析的理想的上样量,同时优化了等电聚焦程序,最终得到的2-D图谱分离效果较为理想。该研究的开展也为苹果叶片蛋白质组学后续研究奠定了基础。     

水牛梭形住肉孢子虫抗原的薄层等电聚焦行为分析

应用薄层聚丙烯酰胺等电聚焦电泳（ＩＦＥ）对水牛梭形住肉孢子虫（Ｓａｒｃｏｃｙｓｔｉｓｆｕｓｉｆｏｒｍｉｓ）抗原进行了分析。结果表明，经ＳｅｐｈａｄｅｘＧ－１００纯化的包囊抗原在电泳图谱上显示３条相距较近的带，等电点分别为６．３０，６．４５，６．６５；缓殖子纯化抗原仅出现１条带，等电点为６．４０     

Effects of a low dose infusion of racemic and S-ketamine on the nociceptive withdrawal reflex in standing ponies

ObjectiveTo investigate the effect of plasma concentrations obtained by a low dose constant rate infusion (CRI) of racemic ketamine or S-ketamine on the nociceptive withdrawal reflex (NWR) in standing ponies.Study designProspective, blinded, cross-over study.AnimalsSix healthy 5-year-old Shetland ponies.MethodsPonies received either 0.6 mg kg⁻¹ racemic ketamine (group RS) or 0.3 mg kg⁻¹ S-ketamine (group S) intravenously (IV), followed by a CRI of 20 μg kg⁻¹minute⁻¹ racemic ketamine (group RS) or 10 μg kg⁻¹minute⁻¹ S-ketamine (group S) for 59 minutes. The NWR was evoked by transcutaneous electrical stimulation of a peripheral nerve before drug administration, 15 and 45 minutes after the start of the bolus injection and 15 minutes after the end of the CRI. Electromyographic responses were recorded and analysed. Arterial blood was collected before stimulation and plasma concentrations of ketamine and norketamine were measured enantioselectively using capillary electrophoresis. Ponies were video recorded and monitored to assess drug effects on behaviour, heart rate (HR), mean arterial blood pressure (MAP) and respiratory rate.ResultsThe NWR was significantly depressed in group RS at plasma concentrations between 20 and 25 ng mL⁻¹ of each enantiomer. In group S, no significant NWR depression could be observed; plasma concentrations of S-ketamine (9–15 ng mL⁻¹) were lower, compared to S-ketamine concentrations in group RS, although this difference was not statistically significant. Minor changes in behaviour, HR and MAP only occurred within the first 5–10 minutes after bolus drug administration in both groups.ConclusionAntinociceptive activity in standing ponies, demonstrated as a depression of the NWR, could only be detected after treatment with racemic ketamine. S-ketamine may have lacked this effect as a result of lower plasma concentrations, a more rapid metabolism or a lower potency of S-ketamine in Equidae so further investigation is necessary.     

家蚕血液酯酶同功酶的研究

采用不连续聚丙烯酰胺凝胶电泳法.测定了24个家蚕品种及杂交种从三龄到后蛹不同发育时期的血液酯酶同功酶酶谱.结果表明:家蚕血液中存在着丰富的酯酶同功酶酶带类型,整个试验可观察到22条酶带,根据其迁移率及染色特点可分为A、B、C、D、E五大染色区.在不同发育阶段中共有13条酶带经常显现,后蛹期主要同功酶酶带活性降低,但非主带A-1区酶带却清楚地显示出来.在幼虫阶段,酶带的数目及活性防着食下量的增多而增人.并观察到A-2-b带与B-2带的表现最为突出,推测A-2-b带可能是家蚕血液部酶同功酶的基本酶带.进一步分析表明,A-2-b带活性与大多数经济性状间呈高度的正相关性.     

葡萄叶片蛋白质双向电泳技术体系的建立

现对葡萄叶片中总蛋白质的双向电泳技术体系进行了初步探讨,比较了不同等电聚集程序、不同pH胶条以及不同SDS-PAGE凝胶浓度的双向电泳效果。结果表明:葡萄叶片蛋白质使用等电聚焦程序B、pH范围为4~7的胶条和12%的SDS-PAGE凝胶可以得到较为理想的双向电泳分析结果;采用7 cm胶条最大可以分离出143个有效蛋白质点。     

香蕉植株内生细菌群落的PCR-DGGE分析

以健康香蕉植株和感染香蕉枯萎病菌Fusarium oxysporum f.sp.cubense(FOC)后的香蕉植株的根茎叶组织为材料,提取样品中的总DNA,扩增细菌的16S rDNA的V3可变区,对扩增产物进行DGGE电泳分析,并对其中18条优势条带进行切胶回收、克隆测序和系统发育分析。结果表明,香蕉健株与病株各组织中所含内生细菌的种群丰富度为根部>假茎>叶片;感病植株组织内生细菌种类比健康植株丰富;BLAST结果为大部分克隆序列与已知细菌16SrDNA基因序列的同源性较高(94%~100%),分别归属于蓝细菌门(Cyanobacteria)、绿弯菌门(Chloroflexi)、放线菌门(Actinobacteria)、变形杆菌门(Proteobacterium)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)和绿菌门(Chlorobi)7大类群;其中一个序列同源性较低(91%),可能代表新的分类单元。