researchers found in the seeds of peas (Pisum sativum) amyloid accumulation reserve protein in the first place Villena, reported in PLoS Biology. This is the first time when vegetable proteins find this. Amyloid accumulation vicilin are formed in the cells of the cotyledons of the pea, their content increases with the maturation of the seed, and after germination decreases. They do not disintegrate under the influence of digestive enzymes and when cooked, retained after preservation and in high concentrations is toxic to mammalian cells.
Amyloid (amyloid fibres, plaques, etc.) — a cluster of protein molecules, is strongly associated beta-pleated sheets. They are capable of self-organization: when multiple protein molecules is in the form of amyloid, and nearby molecules also will be her. In addition, proteins in the amyloid often form a connection with polysaccharides, or with certain other molecules. These persistent education identify patients with various serious and incurable diseases, including Alzheimer’s disease. A certain amount of amyloid is present in healthy cells, such as the hippocampus in mammals and the mushroom bodies of insects, and contributes to memorization. Important they are for storage of peptide hormones, the creation of biofilms (bacteria), the formation of specialized hyphae (in fungi), and several other purposes.
Interestingly, although the word “amyloid” is associated with the starch, and was originally used to refer to carbohydrates in plant cells (and is still the amyloplasts called the structure forming starch) in plants, proteins in form of amyloid accumulations have not been found. However, bioinformatics analysis of sequences of amino acids in the various vegetable proteins showedthat the existence of amyloid in the cells of this group of organisms is possible: roughly speaking, amino acids in certain proteins are in this order that can form characteristic of amyloid structure. According to him, the most likely candidates for the formation of amyloid in plants — globulin proteins “size” 11S and 7S (Svedberg units; determine the deposition rate, but not the actual size of the molecules)
The authors of this analysis, the staff of the all- research Institute of agricultural Microbiology and severaln scientific institutions, headed by Anton Nizhnikov checked the status of a number of globulin proteins in the seeds of one of the model plants of peas (Pisum sativum). For content of various proteins in the seeds was monitored from the moment of their formation to germination. The amyloid was identified by liquid chromatography and also by the action of ionic detergent (in contrast to other forms of proteins, amyloid accumulation after exposure is stored).
It turned out that amyloid accumulation in the seeds of peas there, and most of it forms a protein vicilin. They serve as a source of nitrogen for seedlings. Most of them appeared in the cotyledons of the seed, which usually stock bean nutrients for the embryos. The contents villimovich amyloid accumulations increased as the ripening seed, but germination after his fall. Apparently, this form of storage protein helps to stabilize him until he will not need the young plant.
Amyloid accumulation was extracted from seeds and look at their properties in vitro and the effect on other organisms. Their presence in the environment, not amyloid molecules Villena contributed to the fact that the second is also formed clusters. On the cell surface of E. coli and in yeast cells, they behaved the same way. Boiled and canned pea seeds were also present amyloid fibrils vicilin. They were resistant to enzymes that destroy proteins, but disintegrated under action of ultrasound.
When villanovy amyloid was injected into culture of yeast cells at a concentration of 0.5 micromol per milliliter and above, almost all of them died. The same happened with the cell culture adenocarcinoma human colon DLD1. It is worth considering that in pea seeds, the concentration of amyloid is significantly lower, therefore, these results do not imply that a pea is dangerous to health.
Surely vicilin not the only plant protein that can form amyloid aggregations. Search for other similar properties should be proteins in seeds and other plant parts that are used for experiencing adverse conditions. Exceptional resistance of amyloid to external influences makes them a reliable form of storage proteins.
The seed remarkably persistent structure. It can be stored without loss of viability tens of thousands of years. The oldest seeds that managed to sproutis the seeds of the Judean date palm age of about two thousand years. And live embryos were removed (and raised them full-fledged individuals) from more old seeds of bladder Campion uzkolisty (or, according to some, Siberian dawn) age 31800 years. In both cases, to preserve the “seed” helping the climate: bones date palms before the arrival of the scientists lay in a hot place with very low humidity in the South-Western coast of the Dead sea, and the fruits Campion in the perennial permafrost on North-East Yakutia.