蜘蛛丝多肽链段结构的优化设计

根据蜘蛛丝氨基酸片段的序列特征,利用 Hyperchem5软件对部分具有β-折叠或螺旋状结构的多肽链段的分子结构进行优化设计,分析了氨基酸种类、聚合度对多肽链段形成特定构象的影响,发现一定的氨基酸片段有形成特定构象的趋势。分子构象的多元化是蜘蛛丝具有优异力学性能的重要原因。     

Glucagon and pancreatic polypeptide immunoreactivities co-exist in a population of rat islet cells

Summary In mammalian pancreas, glucagon and pancreatic polypeptide have been shown to be present in distinct cell types. The present communication reports that, in rat pancreas, in addition to glucagon and pancreatic polypeptide cell populations, there is a small population of cells which contain both glucagon and pancreatic polypeptide immunoreactivities.     

人胎基底动脉肽能神经的支配—免疫细胞化学方法研究

以16例24周龄至38周龄死亡人胎的基底动脉作材料,用免疫细胞化学方法(ABC法和PAP法)研究某些肽能神经纤维的分布。于光镜下观察到基底动脉壁的外膜中存在血管活性肠肽(VIP)样、P物质(SP)样和生长抑素(SOM)样免疫反应阳性神经纤维。这些神经纤维呈树枝样、爪样、索条样或点状,有些集合成束。在靠近中膜的外弹性膜附近,神经纤维较为密集。但中膜及内膜未发现神经纤维。不同周龄胎儿的基底动脉壁中,此三种免疫反应阳性纤维的分布区域和型式无明显差异。     

Ontogenic development of peptide hormones in the mammalian fetal pancreas

Summary The ontogeny of insulin, glucagon, PP and somatostatin in the mammalian fetal pancreas has been examined in recent years largely by immunocytochemistry and in some instances by radioimmunoassay. Complete ontogenic data are available only for the rat, human pig and sheep. Figure 3 compares the time of appearance of the endocrine cell-types within the fetal pancreas when the periods of gestation of the four species are converted to a uniform scale. The striking ontogenic difference in the rat probably reflects the immaturity of the rodent fetus at birth compared with the human, pig and sheep. In the fetal pancreas, differences in cell number of glucagon and PP cells in the dorsal and ventral lobes become apparent from an early gestational period. Factors responsible for the functional and structural maturation of the fetal pancreatic endocrine cells and the processes involved in pancreatic organogenesis are poorly understood. Studies in these areas would have clinical implications since it may be possible in the future to employ agents for selective replication of fetal -cells for transplantation in patients with Type I diabetes, bearing in mind that such cells must have the capacity to respond to normal stimuli and repressors when transplanted. The presence of the other islet cell-types may be obligatory for these appropriate responses. This would require a more complete knowledge of those factors which produce the normal selectivity of the four hormonal cell-types.     

蛋白质和多肽药物质量控制中分析方法的应用概况

蛋白质和多肽药物研究进展迅速,蛋白质和多肽药物的分析方法和相关检测设备也在不断地更新和改进,从而为该类药物的开发研究、质量控制和临床应用都提供了重要的手段。     

萍蓬草光合膜光化学活性及多肽组分分析

研究了睡莲科植物萍蓬草（Ｎｕｐｈａｒ ＰｕｍｉｌｕｍＤＣ）类囊体ＰＳＩ、ＰＳⅡ电子传递活性、吸收光谱等光化学活性及类囊体膜的多肽组分,并与睡莲科植物睡莲（Ｎｙｍｐｈａｅａ ａｌｂａＬ）及陆生植物青菜（Ｂ．ｃｈｉｎｅｓｉｓＬ．）进行比较,结果显示：相同条件下薄蓬草类囊体膜ＰＳＩ、ＰＳⅡ电子传递活笥较睡莲高,较青菜低;室温吸收光谱与采相似,在蓝紫光区域（４３０ｎｍ）和红光区域（６８０ｎｍ）的吸收峰都较     

脱脂豆粕多肽络合盐的应用特性研究

利用1398中性蛋白酶水解脱脂豆粕后形成的多肽与微量的锌、亚铁络合。制备出的多肽络合锌、多肽络合亚铁为原料,研究其对食品的抗氧化作用和对生物吸收率的影响．结果表明,添加多肽络合锌和多肽络合亚铁的猪油和鱼油的过氧化值均低于对照组,表明其具有抗氧化性;将多肽络合锌和多肽络合亚铁喂食小鼠,得出其有一定的生物吸收利用率,故可作为食品营养强化剂。     

植物胞外多肽与人细胞因子的结构特征比较

植物细胞外多肽信使已经被证实是植物信号转导中重要的第一信使,运用生物信息学的方法,分析比较了已知的植物胞外多肽和人的细胞因子的氨基酸序列,发现这些来自不同界别的胞外多肽具有某些共同的结构特征,利用在线工具对胞外多肽的结构特征进行了验证,并根据细胞外多肽的结构特征推测了钙调素受体的三维结构,这些结果对发现新的植物胞外多肽及推测其可能的受体有重要意义.     

低聚糖和多肽联合补充对大鼠糖原代谢的影响

研究了联合补充低聚糖和多肽对中等强度长时间运动后大鼠肌糖原及肝糖原代谢的影响.结果表明:运动前补充低聚糖和多肽能显著节约体内肌糖原的使用;运动后慢肌糖原合成过程中存在先快后慢的恢复规律;运动前及运动后即刻结合补充低聚糖和多肽能显著促进运动后肝糖原的恢复;在运动后慢肌糖原恢复过程中,肝糖原先于肌糖原恢复.