Structural and Functional Characterization of a New Double Variant Haemoglobin (HbG-Philadelphia/Duarte 𝛼^{𝟔𝟖Asn→Lys}_𝟐𝛽^{𝟔𝟐Ala→Pro}_𝟐)

Table 1

Oxygen binding properties of purified HbG-Philadelphia/Duarte.

	pH	log p50	𝑛50	p50HbA/p50HbG Philadelphia/Duarte
	6.47	0.81 (1.13)	2.56 (2.71)	2.09
−5 mM 2,3-DPG	7.05	0.67 (0.94)	2.54 (2.67)	1.86
	7.4	0.41 (0.66)	2.64 (3.0)	1.77
Alkaline Bohr effect		−0.43 (−0.50)
	6.54	1.09 (1.47)	2.40 (2.74)	1.40
+5 mM 2,3-DPG	7.18	0.88 (1.30)	2.29 (2.78)	2.63
	7.44	0.67 (1.0)	2.45 (2.96)	2.14
Alkaline Bohr effect		−0.46 (−0.52)

Corresponding values for HbA are given in parentheses.
Data were obtained with 0.1 M Bis-Tris/Tris buffer + 0.1 M NaCl at 25°C. O₂ pressure is expressed in Torr units.
An average S.D. of 5% for values of log p₅₀ was calculed.