Local conformation change

Binding of O2 to one of the subunits of the T form leads to a local conformational change that weakens the association between the subunits. Increasing O2 partial pressure thus means that more and more molecules convert to the higher-af nity R form. This cooperative interaction between the subunits increases the O2 af nity of Hb with increasing O2 concentrations—i. e., the O2 saturation curve is sigmoidal (see p. 282). 

Fourmy D, Yoshizawa S, Puglisi JD (1998) Paromomycin binding induces a local conformational change in the A-site of 16S rRNA. J Mol Biol 277 333-345... 

The structural variations can affect the width of the major groove, the extent of base stacking, as well as the tilt of the basepairs to each other. The local conformational changes are sequence dependent and can be intrinsic properties and thus permanent occurrences they can, however, also be induced by protein binding. The DNA sequence can thus serve a double purpose for the recognition between DNA and protein. 

In the temperature range where side group motions occur, leading to a secondary transition like the ft transition of PMMA, these motions soften the surrounding of the moving units and, consequently, allow local conformational changes of the main chain under a lower stress than in the low temperature case. In the case of the ft transition of PMMA, on the low temperature side, the ester group n-flips are localised and the mechanism above described operates. 

Interestingly, the initial tubulin coordinates used in the study of HTI-286 are those of straight tubulin in 2D sheets (PDB entry 1JFF) [83], The X-ray structure of the T2R complex with vinblastine showed that the unpolymerized tubulin heterodimer is bent and that there are local conformational changes at the interdimer interface in comparison with straight tubulin [13], The discrepancy between the experimental [12] and computationally predicted [31] binding modes of colchicine has been attributed to the fact that the computational model was derived from... 

Hammarstrom, P., Owenius, R., Martenson, L-G., Carlsson, U., and Lindgren, M. (2001) High resolution probing of local conformational change in proteins by the use of multiple labeling unfolding and self -assembly of human carbonic anhydrase II monitored by spin, fluorescent, and chemical reactivity probs, Biophys. J. 80, 2867-2885. 

Likhtenshtein, G.I., and Bobodzhanov, P. Kh. (1968) Investigation of die structure and local conformational changes of proteins and enzymes using double paramagnetic labels. Biofizika, 13, 757-764. 

A protein S, the cofactor of activated protein C, has four EGF-like modules in tandem. The stracture of N-terminal EGF modules is very similar to that of non-calcium-binding modules. Calcium binding only results in a limited local conformational change. The N-terminal loop is better defined and moves toward the major /3-sheet. The N-terminal non-catalytic Gla and EGF-like domains provide coagulation serine proteases with different calcium affinities for certain biological membranes, and also mediate protein-protein interactions. ... 

The conformational changes elsewhere in the molecule are very small. Thus, the switching on of enzymatic activity in a protein can be accomplished by discrete, highly localized conformational changes that are Piggered by the hydrolysis of a single peptide bond. 

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