title: Purification and antipathogenic activity of lipid transfer proteins (LTPs) from the leaves of Arabidopsis and spinach.
abstract: Two homogeneous proteins active in vitro against the bacterial pathogen Clavibacter michiganensis subsp. sepedonicus were obtained from a crude cell-wall preparation from the leaves of Columbia wild-type Arabidopsis. The N-terminal amino acid sequences of these proteins allowed their identification as lipid transfer proteins (LTP-a1, LTP-a2); the LTP1-a1 sequence was identical to that deduced from a previously described cDNA (EMBL M80566) and LTP-a2 was quite divergent (44% identical positions). These proteins were not detected in the cytoplasmic fraction by Western-blot analysis. Proteins LTP-s1 and LTP-s2 were similarly obtained from spinach leaves; LTP-s1 was 91% identical to a previously purified spinach LTP (Swiss Prot P10976), and LTP-s2 was moderately divergent (71% identical positions). About 1/3 of the total LTPs were detected in the cytoplasmic fraction from spinach by Western-blot analysis. Concentrations of these proteins causing 50% inhibition (EC-50) were in the 0.1-1 microM range for the bacterial pathogens C. michiganensis and Pseudomonas solanacearum and close to 10 microM for the fungal pathogen Fusarium solani.
authors.affiliation: Laboratorio de Bioquímica y Biología Molecular, ETS Ingenieros Agrónomos, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Segura
authors.forename: M
authors.initials: M
authors.lastname: Moreno
authors.forename: F
authors.initials: F
authors.lastname: García-Olmedo
mesh_terms: D000595:Amino Acid Sequence; D052179:Antigens, Plant; D017360:Arabidopsis / Q000378:metabolism* / Q000382:microbiology; D001420:Bacteria, Aerobic / Q000187:drug effects / Q000472:pathogenicity; D002352:Carrier Proteins / Q000302:isolation & purification* / Q000633:toxicity*; D018076:DNA, Complementary; D005670:Fusarium / Q000187:drug effects / Q000472:pathogenicity; D006093:Gram-Positive Asporogenous Rods / Q000187:drug effects* / Q000472:pathogenicity; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins; D011549:Pseudomonas / Q000187:drug effects / Q000472:pathogenicity; D017386:Sequence Homology, Amino Acid; D014675:Vegetables / Q000378:metabolism* / Q000382:microbiology
chemical_list: D052179:Antigens, Plant; D002352:Carrier Proteins; D018076:DNA, Complementary; D010940:Plant Proteins; C511920:lipid transfer proteins, plant