Thermal denaturation curve

Another common indication of protein stability is the concentration of either urea or GnHCl required to unfold half of the protein available. This concentration, given the symbol [D]i/2, is analogous to the Tm value from thermal denaturation curves. Increase or decrease in [D]i/2 is presumed to indicate a corresponding increase or decrease in protein stability, respectively. Analysis of these curves can also provide thermodynamic information [123-126]. As these experiments can be done at any temperature, they are more useful in that they can provide information regarding stability at or near room temperature. 

Figure 2 Thermal denaturation curves for wild-type MntR (8 xM) monitored by CD spectroscopy at 222 nm unfolding of apo MntR (open squares) and of MntR in the presence of 1.0mMMg +, Ca +, Mn +, Co +, Ni +, and Cd +. Buffer 20mM HEPES, pH 7.2 at 4 °C, 200 mM NaCl, 5% (v/v) glycerol. Pathlength 2 mm. (Reprinted with permission from Golynskiy, Davis, Hehnann and Cohen. 2005 American Chemical Society)...

Tubular membrane tension/mucosal DNA thermal melting point midpoint of thermal denaturation curve Transmembrane Trimethylamine oxide Transmembrane domain Trimethylsilyl thimersol Tobacco mosaic virus Treose nucleic acid 5-thio-2-nitrobenzoate... 

Unfolding can also be induced by temperature, and thermal denaturation curves (melting curves) are experimentally easier to obtain, since measurements are carried out only on a single protein solution. It is also easy to check the reversibility of the process by slowly cooling the denatured protein solution. The parameter A G°s can be obtained from melting curves provided either that the van t Hoff plot... 

Figure 2. Circular Dichroism of ZDD. A, Spectra of the fully zinc-coordinated form (native), a Zn2 species, and an apo-form of the fragment. B, Thermal denaturation curves of native ZDD as compared to a Zn2 species.

Figure 5 Thermal denaturation curves (upper) and emulsifying properties (bottom) of polymannosyl and oligomannosyl lysozymes constructed by genetic engineering. , wild-type lysozyme O, polymannosyl lysozyme , oligomannosyl lysozyme.

Shirley B A (1992). Protein conformational stability estimated from urea, guanidine hydrochloride, and thermal denaturation curves. In T J Ahern, M C Manning, (eds.). Stability of Protein Pharmaceuticals Part A Chemical and Physical Pathways of Protein Degradation Plenum Press, New York, pp. 167-194. 

A Cp can also be obtained from thermal denaturation followed by spectroscopic probes if cold denaturation can be observed (Fig. 1C, thin solid line). Thermal denaturation curves followed by CD or fluorescence can be fit by nonlinear regression... 

Polarimefrv thermal denaturation curves Fraction of nicked or fragmented molecules Condell el al., 1988... 

Fig. 7. Typical thermal denaturation curve plotting the uv absorbance at 260 nm (A260) of a polynucleotide sample versus temperature. The melting temperature (Tm) of this sample is ca 48° C.

Algorithms for the analysis of thermal denaturation curves of DNA and the computer simulation of the fine structure have been considered in a review. The melting curve of a DNA molecule has been decomposed into components with an assumed Gaussian form, and the melting curve and denaturation map of a DNA of known sequence has been obtained using a modification to the Zimm model, which is designed to reduce numerical instability. A recursion relation technique has been developed and applied to fluctuations in the superhelical structure of DNA, and to elucidate the effect of torsional stress upon DNA helix-coil transition. ... 

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