Albany 2015:Book of Abstracts

Albany 2015
Conversation 19
June 9-13 2015
©Adenine Press (2012)

Molten globule behavior of Apicomplexan protein P2 from Plasmodium falciparum and Toxoplasma Gondii

The P2 protein in Plasmodium falciparum has a high tendency to oligomerize, which seems to drive many of its non-ribosomal functions. During nuclear division of the parasite inside RBC, Plasmodium falciparum P2 translocates to the RBC surface as a tetramer. From a systematic study using variety of biophysical techniques, NMR spectral characteristics and relaxation dispersion measurements under different conditions of pH and/or urea concentrations, we deduce that (i) PfP2, an almost entirely helical protein, forms a molten globule monomer at low pH, (ii) at physiological pH, and at micro-molar concentrations, PfP2 is a stable tetramer wherein two dimers associate sideways with close packing of helices at the interface, and (iii) the molten globule characteristic of the monomer is preserved in the tetramer. P2 protein from toxoplasma gondii also oligomerizes and similar observations were made for toxoplasma gondii P2 protein. This dynamism in the structure of P2 may have functional implications since it is known that different kinds of oligomers are transiently formed in the parasite in case of Plasmodium falciparum.

Pushpa Mishra 1
Shobhona Sharma 2
Ramakrishna V. Hosur 1,3*

1 Department of Chemical sciences
Tata Institute of Fundamental Research
Mumbai, India
2 Department of Biological sciences
Tata Institute of Fundamental Research
Mumbai, India
3 UM-DAE Centre for Excellence in Basic Sciences
Mumbai University Campus,
Mumbai, India