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Bioactive peptides acting on animals and plants

作用于动植物的生物活性肽

基本信息

批准号：
11460045
负责人：
YOSHIKAWA Masaaki
金额：
$ 9.09万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Ala-Met-Lys-Pro-Trp, which was isolated as a pollen tube-extending peptide from casein digest exhibited weak hypertensive activity after iv. administration in rats. While hypertensive activity of the peptide was blocked by an angiotensin AT1 antagonist, the pollen tube-extending activity was not affected by the antagonist.Soymetide which was isolated as an immunostimulating peptide from soybean digest acts through fMLP receptor. Soymetide-4 (Met-Ile-Thr-Leu), the minimum peptide to show immunostimulating activity promoted extension of tea pollen tube. It also stimulated extension of Brassica campestris root at 10^<-7>M.The activity seems to be not a mere nutritional effect since the extension was inhibited by the peptide above 10^<-4>M.Soymetide-4 exhibited the highest activity both for stimulation of pollen tube and root exyension among the soymetide fragment peptides of various length. Ala-Met-Lys-Pro-Trp derived from casein as descibed above also stimulated root extension. Although fMLP weakly stimulated pollen tube extension, it was inactive for root.Methioninyl residue in soymetide-4 was essential for both immunostimulation and extension of pollen tube and root. However, the peptide showing the maximum activity was different for these three activities among soymetide-4 derivatives ; the best peptide for immunostimulation, pollen tube extension and root extension was MIWL, MRGG and M (O) TL, respectively. These results suggest that receptors mediating these three activities are different each other though elevation of intracelullar calcium level is the common post-receptor event following them.

Ala-Met-Lys-Pro-Trp是从酪蛋白酶解物中分离得到的一种花粉管延伸肽，静脉注射后表现出较弱的降压活性。大鼠给药。当该肽的高血压活性被血管紧张素AT 1拮抗剂阻断时，花粉管延伸活性不受拮抗剂的影响。甜菜碱甲肽-4（Met-Ile-Thr-Leu）是表现免疫刺激活性的最小肽，它能促进茶树花粉管的伸长。在10 μ M浓度下，大豆肽片段对油菜根的伸长也有促进<-7>作用，这种作用似乎不仅仅是一种营养效应，因为10 μ M以上的肽对根的伸长有抑制<-4>作用。如上所述的来自酪蛋白的Ala-Met-Lys-Pro-Trp也刺激根延伸。虽然fMLP对花粉管的伸长有微弱的刺激作用，但对根无活性，soymetide-4中的甲硫氨酸残基对免疫刺激和花粉管及根的伸长都是必不可少的。然而，在大豆肽-4衍生物中，对这三种活性表现出最大活性的肽是不同的;免疫刺激、花粉管延伸和根延伸的最佳肽分别是MIWL、MRGG和M（O）TL。这些结果表明，介导这三种活性的受体是不同的，但细胞内钙离子水平的升高是它们共同的受体后事件。