Mechano-chemical effects of Ca(2+) in cross-linked troponin-C films.
Changes in troponin C (TnC) conformation upon Ca(2+) binding forms the basis for regulatory and structural functions of TnC molecules. In the present study, Ca(2+)-induced conformational changes in TnC were observed by mechanical measurements. TnC films were prepared by drying or electrospraying TnC solutions, cross-linked with glutaraldehyde, and isometric tension and stiffness measured as a function of pCa. An increase in Ca(2+) from a pCa of 9 to 4 induced large-scale mechanical changes in the TnC films causing several percent shrinkage of the unloaded films. This shrinkage could be partially assigned to Ca(2+) binding to the Ca(2+)/Mg(2+) sites of TnC.
Department of Anesthesiology, Mayo Foundation, Rochester, MN 55905, USA. boukatina.anna@mayo.edu
Anna E
AE
Bukatina
Victor N
VN
Morozov
Nikolai B
NB
Gusev
Gary C
GC
Sieck
D000818:Animals; D002118:Calcium / Q000737:chemistry*; D008024:Ligands; D011817:Rabbits; D019209:Troponin C / Q000737:chemistry* / Q000378:metabolism
D008024:Ligands; D019209:Troponin C; D002118:Calcium