title: A novel lectin from Pseudostellaria heterophylla roots with sequence simularity to Kunitz-type soybean trypsin inhibitor.
abstract: From the roots of the Chinese medicinal herb Pseudostellaria heterophylla a single-chained lectin with a molecular weight of 36 kDa and high hemagglutinating activity was isolated. The lectin was adsorbed on DEAE-cellulose in 10 mM Tris-HCI buffer (pH 7.4) and was eluted by the same buffer containing 50 mM NaCl. It was adsorbed on SP-Sepharose in 10mM NH4OAc (pH 4.5) and eluted by approximately 0.5 M NaCl in the same buffer. The hemagglutinating activity of the lectin could not be inhibited by a large variety of monosaccharides, but was largely abrogated by exposure to 0.05 M HCl, 0.05M NaOH or 80 degrees C. However, about 50% of the activity remained after exposure to 0.025M NaOH or 40 degrees C. Despite possession of an N-terminal sequence exhibiting some similarity to thaumatin-like proteins with antifungal activity, the lectin was devoid of antifungal activity. The lectin exerted some inhibitory effect on the glycohydrolases alpha-glucosidase, beta-glucosidase and beta-glucuronidase which are involved in HIV infection but had no suppressive action on human immunodeficiency virus-type 1 reverse transcriptase.
authors.affiliation: Department of Microbiology, China Agricultural University, Beijing.
authors.forename: H X
authors.initials: HX
authors.lastname: Wang
authors.forename: T B
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000818:Animals; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors; D006385:Hemagglutination Inhibition Tests; D006386:Hemagglutination Tests; D006358:Hot Temperature; D006851:Hydrochloric Acid / Q000494:pharmacology; D037102:Lectins / Q000737:chemistry* / Q000494:pharmacology; D010936:Plant Extracts / Q000737:chemistry* / Q000494:pharmacology; D037121:Plant Lectins; D018517:Plant Roots / Q000737:chemistry*; D011817:Rabbits; D012972:Sodium Hydroxide / Q000494:pharmacology; D014360:Trypsin Inhibitor, Kunitz Soybean / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D004365:Drugs, Chinese Herbal; D004791:Enzyme Inhibitors; D037102:Lectins; D010936:Plant Extracts; D037121:Plant Lectins; D012972:Sodium Hydroxide; D014360:Trypsin Inhibitor, Kunitz Soybean; D006026:Glycoside Hydrolases; D006851:Hydrochloric Acid