title: Purification and characterisation of an inhibitor of a cathepsin B-like proteinase from sunflower seed.
abstract: Cathepsin B is a vitally important enzyme in various physiological processes and in tumor invasion and metastasis. A cathepsin B inhibitor, HCB-SunI, was identified and purified from sunflower seeds, Helianthus annuus, using ammonium sulfate precipitation and two steps of conventional chromatography. The molecular mass of HCB-SunI was estimated to be 12 kDa by SDS-PAGE and 12.32 kDa by MALDI TOF MS. Its N-terminal amino acid sequence was determined to be: PYGGGGTESG. HCB-SunI not only inhibited Helicoverpa cathepsin B (HCB) but also decreased the growth of HeLa and glioma cells by 7-27% and 6-22%, respectively, when the cells were grown in a final concentration of 0.002-0.008 microM inhibitor.
authors.affiliation: School of Life Sciences, Shandong University, Jinan 250100, China.
authors.forename: Xin-Chang
authors.initials: XC
authors.lastname: Zhang
authors.forename: Hong-Lian
authors.initials: HL
authors.lastname: Shao
authors.forename: Jin-Xing
authors.initials: JX
authors.lastname: Wang
authors.forename: Xiao-Fan
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D002401:Cathepsin B / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D045744:Cell Line, Tumor; D002845:Chromatography; D004353:Drug Evaluation, Preclinical; D004591:Electrophoresis, Polyacrylamide Gel; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005910:Glioma / Q000473:pathology; D006367:HeLa Cells; D006368:Helianthus; D006801:Humans; D008970:Molecular Weight; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D004791:Enzyme Inhibitors; D010936:Plant Extracts; D002401:Cathepsin B