Characterization studies on cadmium-mycophosphatin from the mushroom Agaricus macrosporus.
A low molecular weight Cd-binding phosphoglycoprotein, cadmium-mycophosphatin, has been isolated from the mushroom Agaricus macrosporus. This protein has a molecular weight of 12,000 dalton and contains no sulfur but a high amount of acid amino acids (Glu, Asp), and carbohydrates (glucose, galactose). Cadmium-mycophosphatin has an isoelectric point less than pH 2, binds cadmium with a dissociation constant of KD = 1.59 X 10 M (pKD = 6.8) and is saturated with 13.5 mole Cd/mole, all Cd-binding sites being equivalent. It is suggested that Cd is bound by phosphoserine groups, similar relations being known from calcium-binding proteins in animals. From A. macrosporus four other low-molecular weight glycoproteins have been isolated which contain sulfur and bind cadmium and copper. The biological significance of these Cd-binding proteins is discussed.
Meisch
H U
HU
Schmitt
J A
JA
D000363:Agaricales / Q000378:metabolism*; D000364:Agaricus / Q000378:metabolism*; D002104:Cadmium / Q000378:metabolism*; D002241:Carbohydrates / Q000032:analysis; D002352:Carrier Proteins / Q000032:analysis / Q000378:metabolism*; D003300:Copper / Q000378:metabolism; D005656:Fungal Proteins / Q000032:analysis / Q000378:metabolism; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism; D008970:Molecular Weight
D002241:Carbohydrates; D002352:Carrier Proteins; C049231:Cd-mycophosphatin, Agaricus macrosporus; D005656:Fungal Proteins; D006023:Glycoproteins; D002104:Cadmium; D003300:Copper