Paredi Maria E, Tomas Mabel C, Crupkin Marcos
Centro Regional Sur (CEMSUR-CITEP)-(INTI), Marcelo T. de Alvear 1168, Mar del Plata 7600, Buenos Aires, Argentina.
J Agric Food Chem. 2002 Feb 13;50(4):830-4. doi: 10.1021/jf010767q.
Denaturation of proteins from striated and smooth muscles of scallop (Zygochlamys patagonica) was studied with differential scanning calorimetry (DSC) by monitoring maximum temperatures of transition and denaturation enthalpies. DSC thermograms of both striated and smooth whole muscles showed two transitions: Tmax 55.0, 79.2 degrees C; and Tmax 54.7, 78.7 degrees C, respectively. The DSC thermograms of myofibrils and actomyosin were similar to those corresponding to their respective whole muscles. As pH and ionic strength increased, the thermal stability of whole muscles decreased. The pH increase (5.0-8.0) significantly (p < 0.01) decreased the denaturation enthalpies (deltaH total, deltaH peakI, and deltaH peakII) of whole striated muscles. A significant decrease (p < 0.05) in the deltaH total and the deltaH peakI was also observed in DSC thermograms of smooth muscles at pH 8.0. Denaturation enthalpies (deltaH total and deltaH peakI) significantly decreased (p < 0.01) when the ionic strength increased from 0.05 to 0.5 in both types of muscles. Striated muscles were more affected than smooth muscles by changes in the chemical environment.
利用差示扫描量热法（DSC），通过监测转变的最高温度和变性焓，研究了巴塔哥尼亚栉孔扇贝横纹肌和平滑肌蛋白质的变性情况。横纹肌和平滑肌整体的DSC热谱图均显示出两个转变：最高温度分别为55.0、79.2℃和54.7、78.7℃。肌原纤维和肌动球蛋白的DSC热谱图与各自整体肌肉的热谱图相似。随着pH值和离子强度的增加，整体肌肉的热稳定性降低。pH值升高（5.0 - 8.0）显著（p < 0.01）降低了横纹肌整体的变性焓（ΔH总、ΔH峰I和ΔH峰II）。在pH值为8.0时，平滑肌的DSC热谱图中也观察到ΔH总和ΔH峰I显著降低（p < 0.05）。当离子强度从0.05增加到0.5时，两种类型肌肉的变性焓（ΔH总和ΔH峰I）均显著降低（p < 0.01）。化学环境的变化对横纹肌的影响比对平滑肌的影响更大。
