Question

Could Cobalt hemoglobin exhibit "cooperative effect", since Co²⁺ could replace Fe²⁺ in hemoglobin?

Answer 1

If Co is to be replaced in place of Fe2 in haemoglobin, the oxygenated form of the complex is colorless whereas, the deoxygenated form of the complex is yellow in colour. The O, binding ability of Cobalt is equally strings like Fe2 .The overall shift in the porphyrin ring geometry upon this replacement is different than what we observed for oxygenated Fe-Hb complex. Cobalt haemoglobin shows similar cooperativity effect as Fe. The mobility of Coo is greater than Feo2, the peroxides which again supports the cooperativity effect of cobalt as like iron in haemoglobin.