Two heavy metal-binding proteins in the midgut gland of the crabCarcinus maenas

✍ Scribed by P. S. Rainbow; A. G. Scott

• Publisher: Springer-Verlag
• Year: 1979
• Tongue: English
• Weight: 719 KB
• Volume: 55
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00397310

✦ Synopsis

TWO heavy metal-binding proteins occur naturally in the midgut glands of C a r ~n u s maenas (L.) collected from the Firth of Clyde, Scotland. These proteins, of approximately 27,000 and 11,500 MW (molecular weight) have previously been described as Cd-binding proteins after their induction by high concentrations of cadmium in the laboratory. The -27,000 MW heavy metal-binding protein is bound to about 0.10 g-at of Cd, 0.70 g-at of Zn and 0.31 g-at of Cu per mole of protein; 7.7, 7.9 and 1.1%, respectively, of the soluble Cd, Zn and Cu in the midgut gland are associated with this -27,000 MW protein (6.7, 1.6 and 0.9% of the total midgut gland Cd, Zn and Cu). The -11,500 MW protein is bound to about 0.04 g-at of Cd, 0.37 g-at of Zn and 1.54 g-at of Cu per mole of protein; 29.3, 31.3 and 41.7%, respectively, of the soluble Cd, Zn and Cu in the midgut gland are associated with this protein (25.7, 6.3 and 34.4% of the total midgut gland Cd, Zn and Cu). Neither heavy metal-binding protein is bound to measurable amounts of lead.