Skip to main content
. Author manuscript; available in PMC: 2009 Aug 18.
Published in final edited form as: Nat Protoc. 2006;1(6):2733–2741. doi: 10.1038/nprot.2006.229

Table 1.

Example Scheme for Titrating of a Protein with Guanidine-HCl*

1A
Tmod1160-359,
10 μM, ml		 2A
Tmod1160-359,
10 μM +
Gn-HCl, 4.8 M, ml		 Total
Volume,
ml		 Gn-HCl, M θ222 nm,
mdeg		 [θ]/l000
deg. · cm2/
dmol
0.20 0.00 0.20 0.00 −30.1 −14.7
0.20 0.05 0.25 0.96 −30.0 −14.6
0.20 0.10 0.30 1.60 −27.5 −13.4
0.20 0.15 0.35 2.06 −23.6 −11.5
0.10 0.10 0.20 2.40 −17.6 −8.6
0.10 0.15 0.25 2.88 −10.9 −5.3
0.10 0.20 0.30 3.20 −6.5 −3.2
0.10 0.25 0.35 3.43 −5.4 −2.6
0.00 0.20 0.20 4.80 −4.3 −2.1
*

In this example, a fragment of tropomodulin 1, an actin and tropomyosin binding protein, (Tmod1160-359), is titrated with guanidine-HCl (Gn-HCl)1. Solution 1A contains Tmod1160-359, 0.24 mg/ml (10 μM), in 100 mM NaCl, 10 mM sodium phosphate, pH 6.5. Solution 2A, contains 0.24 mg/ml Tmod1160-359 in 100 mM NaCl, 10 mM sodium phosphate and 4.8 M Gn-HCl, pH 6.5. The titration is performed in a cuvette with a 0.1 cm path length and a sample volume capacity of 0.35 ml.