TABLE 2.

Summary of the two-dimensional NMR chemical shifts for the [¹³C^β]Cys free amino acid in the absence and presence of diamide, NaOH, and heme

Shown are NMR chemical shifts (¹³C,¹H) of [¹³C^β]Cys free amino acid (3 mg/ml) in the absence and presence of diamide (2.5 mm), NaOH (0.1 n, pH 12), or heme (300 μg/ml, pH 12). Spectra were recorded at 298 K in 50 mm potassium P_i, pH 7.4, 10% D₂O buffer. ppm, chemical shift in parts per million of the spectrometer frequency.

[13Cβ]Cys free amino acid	Reduced [13C]Cys	Oxidized [13C]Cys
	ppm	ppm
Alone	27.8:3.03
	27.8:2.98
With diamide		40.5:3.34
		40.5:3.13
With NaOH	27.8:2.98
With heme	27.8:3.02	40.0:3.30
	27.8:2.93	40.0:3.07