Bovine liver rhodanese is a single polypeptide of 293 amino acids in which the halves of the molecule assume analogous tertiary structures in the absence of substantial sequence homology. The sulphur atom transferred during catalysis is bound in persulphide linkage to Cys-247. Substrate binding seems to involve Arg-186 and Lys-249.

No abstract

No abstract

Mild trypsinolysis of Helix pomatia beta-hemocyanin leads to the formation of tubular polymers after removal of the collar part [van Breemen, J.F.L., Wichertjes, T., Muller, M.F.J., van Driel, R., and van Bruggen, E.F.J. (1975) Eur. J. Biochem. 60, 129--135]. Three-dimensional image reconstruction from electron micrographs of negatively stained tubular polymers showed: (a) alternating deep and shallow grooves in between the 10 helical chains, (b) the presence and position of two domains within each morphological wall-unit of the Mellema and Klug model [Mellema, J. E. and Klug, A. (1972) Nature (Lond.) 239, 146--150]. Optical diffraction of oxy and deoxygenated tubular polymers indicate a significant decrease in diameter with a concomitant increase in length upon deoxygenation.

No abstract