TY - JOUR T1 - Conformational transitions of cinnamoyl CoA reductase 1 from leucaena leucocephala JF - International Journal of Biological Macromolecules Y1 - 2014 A1 - Sonawane, Prashant D. A1 - Khan, Bashir Mohammad A1 - Gaikwad, Sushama M. KW - Aggregation Cinnamoyl CoA reductase KW - Conformation KW - Molten globule KW - Thermostability KW - Unfolding AB -

Conformational transitions of cinnamoyl CoA reductase, a key regulatory enzyme in lignin biosynthesis, from Leucaena leucocephala (L1-CCRH1) were studied using fluorescence and circular dichroism spectroscopy. The native protein possesses four trp residues exposed on the surface and 66% of helical structure, undergoes rapid structural transitions at and above 45 C and starts forming aggregates at 55 C. LI-CCRH1 was transformed into acid induced (pH 2.0) molten globule like structure, exhibiting altered secondary structure, diminished tertiary structure and exposed hydrophobic residues. The molten globule like structure was examined for the thermal and chemical stability. The altered secondary structure of Ll -CCRH1 at pH 2.0 was stable up to 90 C. Also, in presence of 0.25 M guanidine hydrochloride (GdnHCI), it got transformed into different structure which was stable in the vicinity of 2 M GdnHCI (as compared to drastic loss of native structure in 2 M GdnHC1) as seen in far UV-CD spectra. The structural transition of LI-CCRH1 at pH 2.0 followed another transition after readjusting the pH to 8.0, forming a structure with hardly any similarity to that of native protein. (C) 2013 Elsevier B.V. All rights reserved.

PB - ELSEVIER SCIENCE BV CY - PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS VL - 64 U3 - Foreign U4 - 3.138 ER -