Molten globule state, of proteins

Tani, F., Murata, M., Higasa, T., Goto, M., Kitabatake, N., and Doi, E. (1995). Molten globule state of protein moleeules in heat-indueed transparent food gels. J. Agric. Food Chem. 43, 2325-2331. 

Redfield C (2004) Using nuclear magnetic resonance spectroscopy to study molten globule states of proteins. Methods Mol Biol 34 121-132... 

Recently, the molten globule state of a-lactalbumin has been shown to possess antitumor activity when complexed with a fatty acid [36,37], and hence the protein may possess secondary biological activity in addition to the primary activity of native a-lactalbumin, i.e., substrate specificity modifier activity in a lactose synthase system [38,39]. The molten globule of a-lactalbumin thus provides an example of the folding intermediate of a protein exhibiting a secondary biological activity. 

Tcherkasskaya O, Ptitsyn O B (1999). Direct energy transfer to study the 3D structure of non-native proteins AGH complex in the molten globule state of apomyoglobin. Protein Eng. 12 485-490. 

Differences in Hydration of Native and Molten Globule States of Soluble Proteins... 

Hirose, M. Molten globule state of food proteins. Trends Food Sci. Technol. 1993, 4,48—51. 

Partially folded and molten globule states are of considerable interest and can be characterized by NMR and additional spectroscopic techniques. The molten globule state of a protein is folded to a given extent it has native-like secondary structural elements and comprises a native-Uke 3D-structure. The main difference from the native state is the absence of important side-chain/side-chain interactions. This intermediate structure can be stabilized under selected conditions making it possible to obtain structural information. Proteins studied in their molten globule form are characterized as ensembles of a diverse set of interchanging conformers... 

A number of proteins are known to pass through a transient intermediate state, the so-called molten globule state. The precise stmctural features of this state are not known, but appear to be compact, and contain most of the regular stmcture of the folded protein, yet have a large side-chain disorder (9). 

Figure 6.2 The molten globule state is an important intermediate in the folding pathway when a polypeptide chain converts from an unfolded to a folded state. The molten globule has most of the secondary structure of the native state but it is less compact and the proper packing interactions in the interior of the protein have not been formed.

This chapter has reviewed the application of ROA to studies of unfolded proteins, an area of much current interest central to fundamental protein science and also to practical problems in areas as diverse as medicine and food science. Because the many discrete structure-sensitive bands present in protein ROA spectra, the technique provides a fresh perspective on the structure and behavior of unfolded proteins, and of unfolded sequences in proteins such as A-gliadin and prions which contain distinct structured and unstructured domains. It also provides new insight into the complexity of order in molten globule and reduced protein states, and of the more mobile sequences in fully folded proteins such as /1-lactoglobulin. With the promise of commercial ROA instruments becoming available in the near future, ROA should find many applications in protein science. Since many gene sequences code for natively unfolded proteins in addition to those coding for proteins with well-defined tertiary folds, both of which are equally accessible to ROA studies, ROA should find wide application in structural proteomics. 

Kuwajima K. The molten globule state as a clue for understanding the folding and coop-erativity of globular-protein structure. Proteins (1989) 6 87-103. 

The chemical shift dispersion (Table 1) and the temperature dependence of the resonance hne shape provides a qualitative measure of whether the structure is well ordered [2]. However, NMR spectroscopy also provides information relevant to the problem of protein folding in the study of the molten globule states. NMR spectroscopic investigations of molten globules may be more demanding than those of ordered proteins due to spectral overlap arising from poor shift dispersion and to short relaxation times that are due to conformational exchange at intermediate rates on the NMR time scale. 

Dickinson, E., Matsumura, Y. (1994). Proteins at liquid interfaces role of the molten globule state. Colloids and Surfaces B Biointerfaces, 3, 1-17. 

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