| Abstract
| - An antifungal protein was isolated from Chinese cabbage (Brassica campestris L. ssp. pekinensis)by buffer-soluble extraction and two chromatographic procedures. The results of matrix-assisted laserdesorption/ionization time-of-flight (MALDI-TOF) mass spectrometry revealed that the isolated Chinesecabbage protein was identical to human FK506-binding protein (FKBP). A cDNA encoding FKBPwas isolated from a Chinese cabbage leaf cDNA library and named C-FKBP. The open reading frameof the gene encoded a 154-amino acid polypeptide. The amino acid sequence of C-FKBP exhibitsstriking degrees of identity with the corresponding mouse (61%), human (60%), and yeast (56%)proteins. Genomic Southern blot analyses using the full-length C-FKBP cDNA probe revealed amultigene family in the Chinese cabbage genome. The C-FKBP mRNA was highly expressed invegetative tissues. We also analyzed the antifungal and peptidyl−prolyl cis−trans isomerase activityof recombinant C-FKBP protein expressed in Escherichia coli. This protein inhibited pathogenic fungalstrains, including Candida albicans, Botrytis cinerea, Rhizoctonia solani, and Trichoderma viride,whereas it exhibited no activity against E. coli and Staphylococcus aureus. These results suggestthat recombinant C-FKBP is an excellent candidate as a lead compound for the development ofantifungal agents. Keywords: Antifungal protein; FKBP; Chinese cabbage; PPIase activity
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