图2. 不同状态下，¹³C全标记和Met甲基¹³C标记的细胞色素c的¹H-¹³C HSQC谱图. (a) 0.1 mmol/L ¹³C全标记细胞色素c，氧化态；(b) 0.1 mmol/L Met甲基选择性¹³C标记细胞色素c，氧化态；(c) 0.1 mmol/L ¹³C全标记细胞色素c，还原态；(d) 0.1 mmol/L Met甲基选择性¹³C标记细胞色素c，还原态. (a)、(c)中Met-6相对信号强度较弱，在(b)、(d)中由于选择性标记了Met末端甲基，所以Met-6的信号明显

Fig. 2. ¹H-¹³C HSQC spectra of ¹³C full-labeled and methyl-¹³C methionine labeled cytochrome c under different states. (a) 0.1 mmol/L ¹³C full-labeled cytochrome c, oxidative state; (b) 0.1 mmol/L methyl- ¹³C labeling methione labeled cytochrome c, oxidative state; (c) 0.1 mmol/L ¹³C full-labeled cytochrome c, reductive state; (d) 0.1 mmol/L methyl- ¹³C methionine labeled cytochrome c, reductive state. (a)、(c) the signal intensity of Met-6 is weak. (b)、(d) the signal of Met-6 is obvious due to the selective labeling of methionine terminal methyl group