Thermal stability of proteins

Steadman B L, Thompson K C, MIddaugh C R, Matsuno K, Vrona S, Lawson E Q and Lewis R V 1992 The effects of surface adsorption on the thermal stability of proteins Bioteoh. Bioengng. 40 8-15... 

Recent publications on the thermal stability of proteins organized in dense solid films, deposited by LB (Nicolini et al. 1993, Facci et al. 1994, Erokhin et al. 1995) and by self-assembling (Shen et al. 1993), leave several questions unanswered, hi particular, it is still not completely clear which parameter is responsible for this phenomenon. Two main factors are discussed when speaking about induced thermal stabihty, namely, decreased water content and molecular close packing (Nicolini et al. 1993). It seems that both of them work in parallel, and unfortunately it is difficult to settle directly which one plays the dominant role. 

This comparative study pointed out molecular close packing as a key parameter responsible for the thermal stability of proteins in films. In the case of BR, this close packing is reached due to the nature of the sample, while LB organization seems to be a more general procedure, for the same goal can be reached for practically any type of protein sample. The last statement was even confirmed by the comparison of the thermal behavior of extracted separated BR in self-assembled and LB films. It was found that BR in LB films is more stable for this kind of sample. The results will be reported in detail elsewhere. 

The comparison of the results on enhanced thermal stability of proteins in LB films reported here and those already published again underlines that molecular close packing is a critical parameter responsible for this phenomenon. 

Krause, A.A. and Niemczyk, H.D. Gas-liquid chromatographic analysis of chlorthal-dimethyl herbicide and its degradates in turfgrass thatch and soil using a solid-phase extraction technique, J. Environ. Sci Health, B25(5) 587-606, 1990. Kresheck, G.C., Schneider, H., and Scheraga, H.A. The effect of DzO on the thermal stability of proteins. Thermod3mamic parameters for the transfer of model compounds from HzO to DzO, J. Phys. Chem., 69(9) 3132-3144, 1965. 

Example 15 in connection with studies on thermal stability of proteins and nucleic acids of the methanogen species the cyclodiphospho-D-glycerate (CDPG) has been synthesized by Priestley from n-butyl-D-glycerate employing dibenzyl diisopropylphosphoroamidite (BnO)2PNiPr2 reagent [43]. 

J. K. Kaushik and R. Bhat, A mechanistic analysis of the increase in the thermal stability of proteins in aqueous carboxylic add salt solutions, Protein Sri. 1999, 8, 222-233. 

The possibilities of application of far-UV circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy in analysis of thermal stability of proteins and structural changes within protein molecules as well in explanation of cross reactivity between food allergens have been described in more detail in Section 3.4. Likewise nuclear magnetic resonance (NMR), especially 2D and multidimensional NMR as well as the method based on diffraction of monochromatic x-rays widely used in examination of tertiary structures of allergens have been described in Section 3.4 and by Neudecker et al. (2001) and Schirmer et al. (2005). 

As discussed earlier in this chapter and also in chapter 6, thermal stabilities of proteins in vivo are influenced by many constituents of the intracellular milieu, including low-molecular-mass protein stabilizers. The process of protein folding, whether during initial synthesis or following heat-induced unfolding, thus will be influenced not only by activities of protein chaperones, but also by the activities of low-mole-cular-mass organic solutes. In principle, heat stress could be ameliorated in part by accumulation of low-molecular-mass protein-stabilizing solutes that favor formation of the compact, folded state of proteins. Such chemical chaperones could complement the activities of protein chaperones. 

Cambillau C, Claverie JM. Structural and genomic correlates of hyperthermostability. J. Biol. Chem. 2000 275 32383-32386. Chakravarty S, Varadarajan R. Elucidation of factors responsible for enhanced thermal stability of proteins a structural genomics based study. Biochemistry 2002 41 8152-8161. 

Ponnuswamy P Muthusamy, R Manavalan, P. Amino acid composition and thermal stability of proteins. Internal. J. Biol. Macro-moL 1982 4 186-190. 

Increased thermal stability of proteins used for biosensors is desirable to allow for robust devices that can withstand a variety of storage, assay, and regeneration conditions. In addition, some evidence suggests that starting from the most stable version of a bioreceptor by yeast surface display will aid in later affinity maturation efforts (38-40). In addition, thermally stable mutants can enable higher expression levels as soluble proteins from yeast or E. coli (19, 20, 38). Thermal stability selection rounds have been carried out on many of the proteins that were later mutated for high affinity (17,19-21, 38 2). 

Nicolini C, Erokhin V, Antolini F et al. thermal stability of protein secondary structure in Langmuir-Blodgett films. Biochim Biophys Acta 1993 1158 273-278. 

Chakravarty, S. Varadarajan. R. Elueidation of faetors responsible for enhaneed thermal stability of proteins A structural genomics based study. Bioehemistry 2002. 41, 8152-816L... 

A frequently used approach to study the thermal stability of proteins is to incubate a protein solution at an elevated constant temperature and to observe the change of certain physical parameters (e.g., CD, IR absorbance, enzyme activity) over periods of minutes or hours. Such measurements deliver precious information for the practical application of the protein in question. On the other hand, it is impossible to extract thermodynamic or structural parameters firom such measurements, as they reflect the loss of native protein caused by a variety of processes. Irreversible thermal denaturation involves complex mechanisms and can lead to precipitation. The rates of such reactions depend on the concentration the rate constants depend on temperature and solution conditions. The order of such reactions can vary from 1 to FTIR has the advantage that it at least allows clear identification of -aggregation in the changes in the amide I band (1600-1700 cm ) of the infrared spectrum. The band component at around 1618 cm reliably reflects the progress of P-aggregation. ... 

The physical nature of hydrophobic effects was previously considered to be entropic. Based on this hypothesis, it has often been claimed that the thermal stabilization of proteins in thermophiles may be correlated with an increase in the number of hydrophobic residues. A critical analysis proved the differences to be statistically insignificant the recent dramatic increase in sequence data from complete genomes of mesophilic and (hyper-) thermophilic bacteria and archaea clearly confirmed this finding (see below). Considering the real meaning of the word hydrophobic, it is clear that the aversion of nonpolar solutes to water becomes more ordinary and less entropy-driven at extreme temperatures, whereas in the mesophilic temperature regime the hydrophobic effect is indeed entropic. Maximum aversion arises at the temperature at which the ftee energy of transfer of nonpolar solutes into water shows its maximum. Under this condition, the entropy (i.e., the temperature derivative of AG) equals zero, so that the hydrophobic effect must be driven by enthalpic contributions, attributable to van der Waals forces in the core of the protein. ... 

FIGURE 11.7 Cosolvent-induced equilibrium shift in the heat denaturation. A comparison between cf 9ln /9lna, (black) and-AG (meshed) of Equation 11.10. The eontribution from the protein-cosolvent interaction changes (meshed) dominate. (Data from S. Shimizu, 2011, Molecular Origin of the Cosolvent-Induced Changes in the Thermal Stability of Proteins, Chemical Physics Letters, 514, 156.)... 

Shimizu, S. 2011. Molecular origin of the cosolvent-induced changes in the thermal stability of proteins. Chemical Physics Letters. 514, 156. 

The effect of activator on the thermal stability of protein - Theory... 

Y. Fujita, Y. Noda, Effect of hydration on the thermal stability of protein as measured by differential scanning calorimetry. Lysozyme - D2O system. Bull. Chem. Soc. Jpn. 52 (1979) 2349-2352. 

Y. Y. Sham, B. Ma, C.-J. Tsai, and R. Nussinov, Proteins Struct., Punct., Bioinf., 46, 308 (2002). Thermal Unfolding Molecular Dynamics Simulation of Escherichia Coli Dihydrofolate Reductase Thermal Stability of Protein Domains and Unfolding Pathway. 

The effect of a ligand on thermal stability of protein can be explicitly accounted for by relating the binding equilibrium to the thermal denaturation process [205]. 

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