Timasheff SN, 1970

Timasheff presents a complete set of pK values in his chapter "Polyelectrolyte properties of globular proteins" in the book Biological Polyelectrolytes edited by Veis (1). "Typical values" are given for the pK values of the ionizable groups, and the reference cited for these data is Tanford's review on the analysis of protein titration curves (2).

Amino acid pK values from Timasheff SN, 1970 (1).

Group

3.7

†‡

ASP

4.4

†¶

GLU

4.4

†§

HIS

7.05

†€

8.0

†¥

CYS

9.5

†

TYR

10.0

†*

LYS

10.0

†•

ARG

†£

† Data from Table I.

‡ The reported range of pK values is 3.6–3.8. The value recorded here is the mean value of this range.

¶ The reported range of pK values is 4.0–4.8. The value recorded here is the mean value of this range.

§ The reported range of pK values is 4.0–4.8. The value recorded here is the mean value of this range.

€ The reported range of pK values is 6.3–7.8. The value recorded here is the mean value of this range.

¥ The reported range of pK values is 7.5–8.5. The value recorded here is the mean value of this range.

* The reported range of pK values is 9.5–10.5. The value recorded here is the mean value of this range.

• The reported range of pK values is 9.6–10.4. The value recorded here is the mean value of this range.

£ The pK value is reported as >13.