Formation of calcium-parvalbumin complex during contraction. A source of "unexplained heat"?

Computer simulation of the kinetics of the distribution of Ca between troponin, parvalbumin and the sarcoplasmic reticulum, during contraction and relaxation shows that parvalbumins can contribute significantly to the rate of relaxation and to the post contractile translocation of calcium. The binding of Ca to parvalbumin is an exothermic process which may account for about 20% of the 'unexplained heat' during contraction.