Peptidergic co-transmission inAplysia: Functional implications for rhythmic behaviors

Despite their ubiquitous presence in the central and peripheral nervous systems, the behavioral functions of peptide co-transmitters remain to be elucidated. The marine molluscAplysia, whose simple nervous system facilitates the study of the neural basis of behavior, was used to investigate the role of peptidergic co-transmission in feeding behavior. Several novel modulatory neuropeptides were purified, and localized to identified cholinergic motorneurons. Physiological and biochemical studies demonstrated that these peptides are released when the motorneourons fire at frequencies that occur during normal behavior, and that the peptides modify the relationship between muscle contraction amplitude and relaxation rate so as to maintain optimal motor output when the intensity and frequency of feeding behavior change.     

Antimicrobial skin peptides and proteins

Human skin is permanently exposed to microorganisms, but rarely infected. One reason for this natural resistance might be the existence of a ‘chemical barrier’ consisting in constitutively and inducibly produced antimicrobial peptides and proteins (AMPs). Many of these AMPs can be induced in vitro by proinflammatory cytokines or bacteria. Apart from being expressed in vivo in inflammatory lesions, some AMPs are also focally expressed in skin in the absence of inflammation. This suggests that non-inflammatory stimuli of endogenous and/or exogenous origin can also stimulate AMP synthesis without inflammation. Such mediators might be ideal ‘immune stimulants’ to induce only the innate antimicrobial skin effector molecules without causing inflammation. Received 9 August 2005; received after revision 21 October 2005; accepted 16 November 2005     

中华鳖常见致病菌对13种抗菌药物的敏感性测定

本研究检测了13种抗菌药物对7株中华鳖致病菌的最小抑菌浓度（MIC），结果表明，从河南郑州的患病中华鳖体内分离的菌株较湖北武汉、湖北咸宁的病鳖体内分离的菌株对各类药物的敏感性强，而从武汉和咸宁产地的病鳖体内分离的菌株其对各类药物的敏感性也有很大差异，结果显示供试菌株对抗菌药物产生了不同程度的耐药性，推测滥用药物和用药方法不当是导致病原菌产生耐药性的原因。     

蚕丝蛋白仿生多肽RAGA16的纳米结构与性能研究

利用天然蛋白质氨基酸序列设计生物仿生材料是近年来兴起的一个热门研究领域.本文中将蚕丝蛋白特征氨基酸序列(Gly-Ala-Gly-Ala-Gly-Ser)部分引入离子互补型多肽RA-DA16-Ⅰ中,设计了新型多肽RAGA16.采用原子力显微镜(AFM)、旋转流变仪(Rheometer)、傅立叶变换红外光谱仪(FTIR)、倒置荧光显微镜等技术对多肽RAGA16的自组装结构、肽链的二级结构、流变学性能以及细胞相容性等进行研究.结果表明,蚕丝蛋白多肽序列引入后,多肽RAGA16具有自组装特性,能够自组装形成致密的纳米级三维网络结构,所形成的水凝胶力学性能明显提高,通过分析得知这可能是由于多肽二级结构中Silk Ⅰ结构成分比例增加所致.荧光染色显示,绝大多数接种于多肽水凝胶中的小鼠前成骨细胞MC3T3-E1能存活,且在不同的三维平面上生长增殖.综上,利用蚕丝蛋白特征序列对RADA16-Ⅰ进行仿生改性后,对拓展多肽材料在生物医学领域的应用具有重要意义.     

Aβ16—22聚集及海藻糖抑制其聚集过程的毛细管电泳检测

淀粉质β（amyloidp,Aβ）多肽是阿尔兹海默症（Alzheimer’Sdisease,AD）的致病蛋白,其疏水核心Aβ16—22具有重要的研究价值．以Aβ16—22为模型多肽,利用毛细管电泳检测方法,分析了Aβ16—22在水溶液和海藻糖溶液中的聚集过程．结果表明,毛细管电泳法不仅能够很好地分离Aβ16-22聚集过程中单体和部分聚体,实现对多肽聚集过程的快速鉴定和分析,同时也可检测海藻糖对Aβ16—22聚集的抑制作用．研究结果可为Aβ聚集抑制剂的高通量筛选和AD治疗中的快速诊断提供实验基础．     

海洋动物寡肽制备与功能特性研究进展

海洋动物中含有大量的活性肽,这些活性肽具有不同的功能特性。其中海洋动物寡肽具有抗氧化、抗肿瘤、抗菌、调节血糖、降低血脂、增强免疫力等重要的生物活性。对这些寡肽的结构,制备工艺,功能特性及其应用前景进行综述,为海洋药物和海洋功能食品的开发提供参考。     

草鱼皮酶解工艺及水解物对嗜热链球菌增殖作用研究

首次研究了水产品蛋白酶解物对乳酸菌的增殖作用。选择草鱼皮为原料,通过蛋白酶Protease P“Amano”6对其进行酶解,其水解物可以作为培养嗜热链球菌增殖的氮源。同时以水解度和水解物对嗜热链球菌的增殖效果为评价指标,并利用正交实验对酶解工艺进行了优化。结果表明,蛋白酶Protease P“Amano”6对草鱼皮最佳的酶解条件为:加酶量3%、料水比1∶3(m/V)、酶解时间7 h、pH 8.0、反应温度45℃。