Comparative study of tobacco Cd-binding peptide and rat liver metallothionein: structures and metal binding properties

Conference · Tue Apr 01 04:00:00 EST 1986 · Plant Physiol., Suppl.; (United States)

OSTI ID:5233213

Reese, R N; Wagner, G J

Comparison of amino acid composition and sequence of tobacco Cd-binding peptide from leaves of plants grown in 3 or 90..mu..M Cd and cultured cells (90..mu..M Cd) with that of rat liver metallothionein (MT) demonstrate the unrelatedness of these molecules. Differences in structure are further shown by the lack of cross reactivity between the Cd-peptide and antibodies raised against MT. Studies of the effects of pII and salt (GuHCl) on Cd binding indicate that MT binds the metal with a higher affinity than does tobacco Cd-peptide (50% dissociation at pH 3.5 and 5.0, respectively). Suspension-cultured tobacco cells were grown in the presence of /sup 35/S and 90..mu..M Cd, 90..mu..M Cd+150..mu..M Zn or 150..mu..M Zn and labeled ligand (/sup 35/S) was only formed when Cd was present. Efforts to demonstrate Zn binding to ligand of Cd-peptide in vitro were unsuccessful. Studies of Cu inducibility and binding to ligand are in progress. MT is inducible by Cu, Zn, Cd and other heavy metal and a number of the proposed functions of this protein in animals involve Cu and Zn binding. The question of Zn and Cu binding to plant Cd-peptides is crucial to understanding the function(s) of these Cd-inducible, Cd-accumulating forms.

• Research Organization: Univ. of Kentucky, Lexington
• OSTI ID: 5233213
• Conference Information: Journal Name: Plant Physiol., Suppl.; (United States) Journal Volume: 80:4
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BONDING
CADMIUM
COMPARATIVE EVALUATIONS
COPPER
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
ELEMENTS
EVEN-ODD NUCLEI
FABRICATION
GLANDS
ISOTOPES
JOINING
LABELLING
LEAVES
LIGHT NUCLEI
LIVER
MAMMALS
METALLOPROTEINS
METALLOTHIONEIN
METALS
NICOTIANA
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PLANTS
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SULFUR 35
SULFUR ISOTOPES
TRANSITION ELEMENTS
VERTEBRATES
ZINC