|Ultima descărcare din IBN:|
| SM ISO690:2012|
CHERDIVARA, Ala; RUDAKOVA, Angela; RUDAKOV, Serghei; KAKHOVSKAYA, Irina; SHUTOV, Andrei. Limited proteolysis of seed storage globulins in relation to their allergenicity. In: International congress on oil and protein crops. 20-24 mai 2018, Chişinău. Chișinău, Republica Moldova: Tipografia "Artpoligraf", 2018, p. 149. ISBN 978-9975-3178-5-6.
|International congress on oil and protein crops 2018|
Congresul "International congress on oil and protein crops" |
Chişinău, Moldova, 20-24 mai 2018
7S and 11S globulins are the most characteristic two-domain storage proteins of seedplants. The domains both of the globulins derived from a common evolutionary ancestorcomprise a b-barrel of antiparallel b-strands conjoined with a group of a-helices. Severaldisordered sequence regions have been specifically inserted into the domain structuresduring evolution of storage globulins. These inserts that are susceptible to limitedproteolysis determine general regularities of storage globulin limited proteolysis, whichoccurs in vitro and during seed germination. The allergenicity both of 7S and 11Sglobulins, especially those from pumpkin and soybean seeds extensively used in manyfood products is well known. Antigen determinants (IgE epitopes) were identified inamino acid sequences of pumpkin and soybean globulins. Remarkably, at least a part ofthese IgE epitopes are located inside the globulin sequence regions potentially susceptibleto limited proteolysis. Thus, it seems likely that limited proteolysis might be used toreduce allergenicity of storage globulins. In correspondence to this suggestion, papainlimited proteolysis of pumpkin seed globulins was studied in this investigation. It wasshown that limited proteolysis of pumpkin 11S globulin that starts from removal ofextended disordered region from the N-terminal domain is further completed with thedetachment of the group of three a-helices. Three of the four IgE epitopes identified inamino acid sequence of pumpkin 11S globulin belong to the detached region. Hence,limited proteolysis leads to an essential lowering of the allergenicity of pumpkin 11Sglobulin. As shown previously, limited proteolysis of soybean 11S globulin occurs in asimilar way that should remove sequences of both IgE epitopes identified in the subunitG1 of this protein. The results of studying of limited proteolysis of pumpkin 7S globulinare encouraging as well. Thus, papain limited proteolysis of this protein starts fromcomplete destruction of the disordered N-terminal extension of the N-terminal domaincontaining six IgE epitopes identified. Further limited proteolysis of the globulin consistsof several additional cleavages, including complete destruction of an additionaldisordered region of the N-terminal domain specifically susceptible for limitedproteolysis, which contains an additional IgE epitope. A high degree of conservation ofamino acid sequences of 11S and also 7S globulins allow suggesting an essential level oftheir immuno-cross reactivity as well as similar regularities of their limited proteolysis.Therefore, limited proteolysis of 11S and 7S storage globulins can be regarded as apromising tool for reducing of their known or predicted allergenicity.