the purified cd-binding protein had the characteristics of metallothioneins : ( 1 ) low molecular weight ( 9.0 kda ) , ( 2 ) high cd content ( 63 micrograms/mg protein ) , ( 3 ) amino-acid composition rich in cysteine ( 18 % ) , basic and acidic amino acids and free from aromatic amino acids , and ( 4 ) an absorption shoulder at near 250 nm .
C0002520
amino-acid
C0815040
acidic amino acids