solutions . several different solutions were used 
 to simulate different states of contraction . relaxing solution ( ph 
 7.0 ) had a composition ( in mm ) of 10 mops , 64.4 k propionate , 
 5.23 mg propionate , 9.45 na2so4 , 10 egta , 0.188 cacl2 , 7 atp , and 10 creatine phosphate . 
 activating solution consisted ( in mm ) of 10 mops , 45.1 k propionate , 5.21 mg propionate , 9.27 na2so4 , 10 egta , 9.91 cacl2 , 7.18 atp , and 10 
 creatine phosphate . glycerol solution consisted of half glycerol and 
 half rigor solution , the latter containing ( in mm ) 50 tris ( ph 7.4 ) , 
 100 nacl , 2 kcl , 2 mgcl2 , and 10 egta . skeletal 
 myofibril preparation . briefly , muscles were dissected 
 bluntly from the backs of rabbits , along the length of the fibers . they were cut into thin strips and tied at both ends to a wooden stick 
 in order to maintain their natural length . the prepared muscle strips 
 were placed in glycerol solution and stored in a freezer at 20 
 c for long - term storage . to obtain myofibril bundles , the muscle 
 strips stored in glycerol solution were transferred to rigor solution 
 for 60 min and then cut into 2 mm segments across the fiber cross 
 section . a tissue segment was diced using a blender ( sorvall omni 
 mixer ) in 7 ml of rigor solution using the following protocol : twice 
  5 s at 1100 rpm , once  5 s at 2500 rpm , and once  
 1 s at 3100 rpm . the resulting myofibril bundles were typically about 
 50 m in diameter and several hundred micrometers long . eight 
 myofibril bundles were probed both in relaxed and activated states 
 to confirm the consistency of the data ( n = 8) . the dissected specimen was stored at 20 
 c in a 50/50 glycerol / rigor solution mixture for long - term storage . 
 to prepare single myofibrils , the muscle tissue was washed in rigor 
 solution and cut using a blender in 2 ml of rigor solution using the 
 following protocol : once  5 s at 2500 rpm and once  10 
 s at 4000 rpm . the resulting myofibrils were typically 45 
 m in diameter and tens of micrometers long . ten single myofibril 
 samples were probed in both activated and relaxed states for consistency 
 ( n = 10 ) . the sr - ftir measurements were made using 
 a nicolet magna 760 ftir bench and a nicolet nic - plan ir microscope 
 with 15 and 32 objectives , at the advanced light source , 
 lawrence berkeley national laboratory , infrared beamline 1.4.3 . myofibril 
 bundle experiments were carried out with a 15 objective , while 
 single myofibril experiments were carried out using a 32 objective . thirty - two scans of ir spectra were collected between 800 and 4000 
 cm at 4 cm resolution and 
 averaged . sr - ftir spectra were initially collected to identify the 
 chemical environment of relaxed muscle . to do this , a drop of myofibril 
 bundle suspension was dispensed onto a caf2 window and 
 then immersed in relaxing solution for 30 min on ice . to collect the 
 sr - ftir spectra of activated muscle , activating solution was drop 
 dispensed onto the myofibril bundle , and measurements were made after 
 the specimen had visibly finished contracting . for obtaining spectral 
 maps of myofibril bundles , a total of eight myofibril bundles were 
 probed in both relaxed and activated states for consistency . for single honeybee 
 myofibrils , 13 myofibrils were probed in both relaxed and activated 
 states . second - derivative 
 analysis was performed for enhancement of spectral resolution using 
 the savitsky  golay method . to 
 minimize evaporation during data collection , the myofibril bundle 
 was kept in a water - tight custom chamber with a tefon fitting .
protein  water 
 interaction plays a crucial role in protein 
 dynamics and hence function . to study the chemical environment of 
 water and proteins with high spatial resolution , synchrotron radiation - fourier 
 transform infrared ( sr - ftir ) spectromicroscopy was used to probe skeletal 
 muscle myofibrils . 
 observing the oh stretch band showed that water 
 inside of relaxed myofibrils is extensively hydrogen - bonded with little 
 or no free oh . in higher - resolution measurements obtained with single 
 isolated myofibrils , the water absorption peaks were relatively higher 
 within the center region of the sarcomere compared to those in the 
 i - band region , implying higher hydration capacity of thick filaments 
 compared to the thin filaments . 
 when specimens were activated , changes 
 in the oh stretch band showed significant dehydrogen bonding of muscle 
 water ; this was indicated by increased absorption at 3480 
 cm1 compared to relaxed myofibrils . 
 these contraction - induced 
 changes in water were accompanied by splitting of the amide i ( c = o ) 
 peak , implying that muscle proteins transition from -helix 
 to -sheet - rich structures . hence , muscle contraction can be 
 characterized by a loss of order in the muscle 
 protein complex , 
 accompanied by a destructuring of hydration water . 
 the findings shed 
 fresh light on the molecular mechanism of muscle contraction and motor 
 protein dynamics .