Isolation of a napin-like polypeptide with potent translation-inhibitory activity from Chinese cabbage (Brassica parachinensis cv green-stalked) seeds. |
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| Authors: | Patrick H K Ngai T B Ng |
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| Affiliation: | Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. |
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| Abstract: | A heterodimeric napin-like polypeptide was isolated from Brassica parachinensis seeds with a procedure involving ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, FPLC-ion exchange chromatography on Mono S and FPLC-gel filtration on Superdex 75. The N-terminal sequence of the 5 kDa subunit of the polypeptide (PAGPFRIPKKRKKEE) showed high homology with other 2S storage proteins like napins and albumins. The polypeptide potently inhibited translation in a cell free system with an IC50 of 6.2 nM. The translation-inhibiting activity of the polypeptide was relatively stable in the pH range 6-11 and in the temperature range 10-50 degrees C. |
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| Keywords: | napin cabbage Brassica parachinensis seeds translation‐inhibitory activity |
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