Stability of β-Lactoglobulin A in the Presence of Sugar Osmolytes Estimated from Their Guanidinium Chloride-Induced Transition Curves

Abstract

The stabilizing role of Trehalose, Sucrose, Sorbitol and Mannitol as sugar osmolytes and polyols on beta-lactoglobulin A (beta-lgA) against its chemical denaturation at pH 2.0 and 25 degrees C has been explored by means of UV-vis spectroscopy. It has been observed that DeltaG (D) (o) of beta-lgA in the presence of 10% (w/v) Trehalose, Sucrose, Sorbitol and Mannitol is increased. We report that the functional dependence of DeltaG (D) of proteins in the absence and the presence of sugar osmolytes on denaturant concentration is linear. Trehalose is found to induce remarkable stability of beta-lgA against chemical denaturation. Furthermore, we assumed sugar osmolytes do not affect the secondary and tertiary structures of the native and GdnHCl-denatured states.

A Distinct Proof on Interplay between Trehalose and Guanidinium Chloride for the Stability of Stem Bromelain

“…In this context, Venkatesu et al revealed that TMAO, betaine, and sarcosine strongly counteract the deleterious actions of urea on α-chymotrypsin. Many studies have found polyols protecting against urea denaturation of the protein. − According to Kumar et al, trehalose acts as potential stabilizer to counterbalance urea-induced unfolding of α-chymotrypsin. Simpson and Kauzmann observed that sucrose counteracts the urea-induced denaturation of ovalbumin.…”

“…Therefore, in present study the potential of trehalose as a protein stabilizer has been further extended by the counteraction study against the denaturation of stem bromelain (BM) caused by guanidinium chloride (GdnHCl). Despite a considerable amount of work done in the field of counteraction in the last five decades, − ,− very few reports are available to establish that trehalose engenders protection of proteins from GdnHCl, which is generally used for protein folding/unfolding experiments. ,,, A majority of the available literature is focused on refolding studies and there is hardly any report mentioning counteraction by trehalose to offset GdnHCl-induced denaturation. Nevertheless, it was quite surprise that there is not even an answer to the first lingering question initiated in counteraction studies, that is, whether trehalose is interfering in the action of GdnHCl by direct interaction or doing its work independently.…”

Beneficial Effect of Sugar Osmolytes on the Refolding of Guanidine Hydrochloride-Denatured Trehalose-6-phosphate Hydrolase fromBacillus licheniformis

“…However, this chaotropic agent is a commonly used protein denaturant for the unfolding/refolding experiments [ 52 ]. Giving that the GdnHCl-induced protein denaturation can be counteracted by polyol-type osmolytes [ 27 , 28 , 33 , 34 , 41 ], our experimental data thus provide more insight into osmolyte-induced protein folding, and the findings are expected to facilitate the practical use of these sugars on the recovery of recombinant proteins from inclusion bodies.…”

Towards increasing chemical and thermal stability of lysozyme with a simulated honey sugar cocktail

“…This phenomenon was further supported by our experimental data as the observed change in the free energy of stabilization, obtained from GdnHCl and thermal denaturation studies of lysozyme in the presence of SHSC was found higher than that observed with equal concentrations of single sugar system. 7,8,39 On this basis, SHSC would have provided greater protein stabilization than equal concentrations of individual sugars and this would have signicantly reduced the concentration of sugar requirement to achieve similar extent of stabilization. Furthermore, osmolyte mixtures have been proven to be more benecial than individual osmolytes in different types of biological applications.…”