Ebulin 1, a nontoxic novel type 2 ribosome-inactivating protein from Sambucus ebulus L. leaves.
A novel type 2 ribosome-inactivating protein (RIP) that we named ebulin 1 has been isolated from leaves of Sambucus ebulus L. (Caprifoliaceae). In vitro ebulin 1 strongly inhibited protein synthesis by rabbit reticulocyte lysates, rat brain, and rat liver cell-free systems but did not affect in vitro plant nor bacterial protein synthesis. Ebulin 1 is composed of two subunits, a catalytic A subunit (M(r) 26,000) and a D-galactose-binding lectin B subunit (M(r) 30,000). Amino-terminal amino acid sequence homology revealed the novelty that the ebulin 1 A-chain shares a high degree of homology not with the A-chain of other type 2 RIPs but rather with the Cucurbitaceae type 1 RIP briodin S and the anti-human immunodeficiency virus type I proteins trichosanthin and TAP 29. Upon treatment with acid aniline the rRNA from ebulin 1-treated rabbit reticulocyte ribosomes released the RNA fragment which is diagnostic of RIP catalytic action. Ebulin 1 was nontoxic to mice up to 2 mg/kg of body weight and did not inhibit protein synthesis in cultured NHC human epithelial cells which are highly sensitive to ricin.
Girbés
T
T
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Valladolid, Spain.
Citores
L
L
Iglesias
R
R
Ferreras
J M
JM
Muñoz
R
R
Rojo
M A
MA
Arias
F J
FJ
García
J R
JR
Méndez
E
E
Calonge
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D004847:Epithelial Cells; D004848:Epithelium / Q000187:drug effects; D037161:Galectins; D006388:Hemagglutinins / Q000302:isolation & purification / Q000378:metabolism; D037102:Lectins / Q000737:chemistry; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity; D014176:Protein Biosynthesis / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000737:chemistry / Q000302:isolation & purification* / Q000633:toxicity; D011817:Rabbits; D012156:Reticulocytes / Q000201:enzymology; D054788:Ribosome Inactivating Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D012270:Ribosomes / Q000187:drug effects; D012276:Ricin / Q000633:toxicity; D017386:Sequence Homology, Amino Acid; D014118:Toxins, Biological
D037161:Galectins; D006388:Hemagglutinins; D037102:Lectins; D046911:Macromolecular Substances; D010940:Plant Proteins; D011500:Protein Synthesis Inhibitors; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological; C107391:ebulin r protein, Sambucus ebulus; D012276:Ricin; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins