Haem disorder in two myoglobins: comparison of reorientation rate.
The globins from sperm whale and from Aplysia limacina myoglobins were reconstituted by addition of stoichiometric ferric protohaem and the Soret c.d. was followed as a function of time. For both reconstituted proteins, the Soret c.d. changes with time, reflecting haem reorientation inside its pocket, as previously described [Aojula, Wilson & Drake (1986) Biochem. J. 237, 613-616] for sperm whale myoglobin. The time course of the c.d. transition is found to be approx. 10 times faster in Aplysia than in sperm whale myoglobin, a result which is in agreement with the known structural and physicochemical properties of the two myoglobins; furthermore, these results confirm that c.d. and n.m.r. data on haem orientation in haemoproteins reflect the same molecular phenomenon.
Dipartimento di Scienze Biochimiche, Università La Sapienza, Roma, Italy.
A
A
Bellelli
R
R
Foon
F
F
Ascoli
M
M
Brunori
D000818:Animals; D001048:Aplysia; D002942:Circular Dichroism; D006418:Heme / Q000032:analysis*; D009211:Myoglobin; D011487:Protein Conformation; D014907:Whales
D009211:Myoglobin; D006418:Heme