Purification and Trypsin Inhibitor Activity of a Sporamin B from Sweet Potato （Ipomoea batatas Lam. 55-2）

Sporamin is a soluble protein in sweet potato, and falls into two distinct homology groups, subfamilies A and B. In this research, a sporamin B was purified and its amino acid sequences, trypsin inhibitor activity （Ti activity） were analyzed. This sporamin B was isolated from sweet potato tubers [Ipomoea batatas （L.） Lam cv. 55-2] through extraction of the water-soluble fraction, dialysis, ultrafiltration and ion-exchange chromatography. Homology determined by polyacrylamide gel electrophoresis showed that mainly one bond appeared in gel after being reduced by SDS （sodium dodecyl sulfate）, or by SDS and 2-mercaptoethanol, or in native situation. By comparing the data of the polypeptide mass Matrix-assisted laser desorption/ionization time-of-flight （MALDI-TOF） mass spectrometry with those of the mass of the theoretical amino acid sequences from NCBI protein database, it was revealed that it was Q40091｜Q40091_IPOBA, sweet potato sporamin B - Ipomoea Batatas （sweet potato） （Batate）. The sequence coverage was 70.6%. N-terminal sequence was SETPV （Ser-Glu-Thr-Pro-Val）. There is a linear relationship between trypsin inhibitor activity （Ti activity） and amounts of this sporamin B （3-18 μg mL-1）. The equation of linear regression was y = 2.5809x ＋ 17.049 （r2 = 0.9966）. There was a curvilinear relationship between Ti activity and amounts of this sporamin B （21-150 μg mL-1）. The equation of curvilinear regression is y = 14.417ln（x） ＋ 23.26 （r2 = 0.9924）. The concentration of sporamin B with Ti activity after heating at 40°C may induce part denature of this sporamin B, and there was no statistic difference after heating at 40, 50, 60°C for 20 min. Heat treatment at more than 90°C leads to a dramatic decrease of trypsin inhibitor efficiency. The results suggested that Q40091｜Q40091_IPOBA was the major sporamin B in sweet potato tubers [Ipomoea Batatas （L.） Lam cv. 55-2], which had strong Ti activity, and was stable to both thermal and DTT （DL-dithiothreitol） relatively.     

浅谈蓝沙还原卡V9.2在高校电子阅览室的应用

阐述了蓝沙还原卡v9.2在保护电子阅览室计算机系统方面上的优势、工作原理、以及使用中常遇到的问题和解决方法。     

内蒙古根河14种野生大型经济真菌生物活性测定

对内蒙古根河市14种野生大型经济真菌的抗菌活性及凝集素、蛋白酶、磷酸酶等生物活性进行了测定。结果表明在被测的14个样品中,具有蛋白酶活性的有4种、具有凝集素活性的有7种、具有抗植物病原真菌活性的有3种,开发和利用这些野生大型经济真菌将取得巨大的经济效益和社会效益。     

不同碳源、氮源对香魏菇菌丝体生长的影响测定

以菌丝体生物量为指标,对香魏菇液体培养基中碳氮营养源进行了优化。结果表明香魏菇菌株能利用多种碳源、氮源,其中碳源以葡萄糖较好;有机氮源优于无机氮源,牛肉膏为较佳氮源。     

2BFJ-6型变量施肥精密播种机的研制

变量施肥精密播种机是精准农业实施的一个重要机械设备.本文针对吉林省中部地区的玉米种植模式,设计了2BFJ-6型变量施肥播种精密播种机.该机一次可完成开沟、变量施肥、精量播种、覆土、镇压等作业.该机变量施肥装置采用GPS实时定位,根据各个地块的测土配方施肥结果,由田间计算机控制液压马达的转速实现实时变量施肥.该机采用勺式精密排种器和单体仿形机构确保了播量的精确和稳定的耕深.实验证实可有效保证变量施肥系统的稳定性和快速响应性及精密播种准确性.     

开拓资讯空间,迈进自学纪元——香港中央图书馆

着重介绍了香港中央图书馆以人为本的建筑思想、服务理念及为读者提供全方位服务的做法。     

以听带动说,培养英语思维与表达——《商务英语听力》教学探析

听力课在英语基础阶段教学中占有重要地位,但是如何才能上好听力课,本文结合英语听力课的特点进行分析,以听带说,培养学生的思维与表达,使听力课充分发挥其功效达到进行得体交流的目的。     

不同种类冷季型草坪草品种耐热性筛选研究

研究比较了2种冷季型草坪草高羊茅和草地早熟禾中5个品种的耐热性.结果表明:高羊茅品种Fawn的耐热性在所有供试品种中表现最差.高羊茅品种守护神Z1和强劲在热胁迫处理的过程中表现稳定,其耐热性显著的优于2个草地早熟禾品种K.B. G和经典.而守护神Z1和强劲之间、K. B. G和经典之间的耐热性差异并不显著.供试的5个草坪草品种的耐热性排序结果为:守护神Z1和强劲>K.B. G和经典>Fawn.     

农艺技术进步与农业机械化发展

农机与农艺属于两门不同学科领域，在农业上的应用，二者相互适应，紧密结合，促进现代农业机械化发展。     

Effect of angiontensin-(1-7) on development of monocrotaline induced pulmonary arterial hypertension and vascular remodeling

AIM: To investigate the effect of angiotensin-(1-7) ［Ang-(1-7)］ on the development of monocrotaline (MCT) induced pulmonary arterial hypertension and vascular remodeling.METHODS: 60 Sprgue-Dawely rats were randomly assigned into three groups: control group, PAH group and PAH+Ang-(1-7) group. Rats in PAH group and PAH +Ang-(1-7) group received 60 mg/kg MCT injection subcutaneously and after 24 h received either saline or 24 μg·kg-1·h-1 of Ang-(1-7) injection via osmotic minipumps for 4 weeks. These rats in control group were firstly injected saline subcutaneously and then received saline injection via osmotic minipumps.RESULTS: After 4 weeks, in PAH group, right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), percentage of wall thickness (WT%) and percentage of wall area (WA%) of pulmonary artery were significantly increased and NO concentration, the level of endothelial nitric oxide synthase (eNOS), eNOS Ser1177-phosphorylation were significantly decreased compared with control group. However, RVSP, RVHI, WT %, WA % were dramatically decreased in PAH +Ang-(1-7) group and NO concentration, the level of eNOS protein, eNOS Ser1177-phosphorylation were significantly increased compared with PAH group.CONCLUSION: These results suggest that Ang-(1-7) could prevent the development of monocrotaline induced pulmonary arterial hypertension and vascular remodeling, which appears to be associated with up-regulation of NO concentration and the level of eNOS protein, eNOS Ser1177-phosphorylation.