The trypsin-inhibitory, immunostimulatory and antiproliferative activities of a napin-like polypeptide from Chinese cabbage seeds. |
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| Authors: | T B Ng Patrick H K Ngai |
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| Institution: | Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. biochemistry@cuhk.edu.hk |
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| Abstract: | A heterodimeric 13.8 kDa napin-like polypeptide has previously been isolated from Chinese cabbage (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. In the present study the N-terminal sequence of the 8.8 kDa subunit of the polypeptide (PQGPQQRPPKLLQQQTNEEHE) was found to have pronounced homology to napins, albumins and trypsin inhibitors, but demonstrated little similarity to the 5 kDa subunit. The polypeptide stimulated nitrite production by mouse peritoneal macrophages and reduced the viability of leukaemia (L1210) cells. It inhibited trypsin with a higher potency than it inhibited chymotrypsin, but was devoid of ribonuclease and antifungal activities. |
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| Keywords: | napin cabbage Brassica parachinensis seeds translation‐inhibitory activity |
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