THERMAL DEPENDENCE STUDIES IN CHLAMYDOMONAS 13C-CENTRIN AND Sfi1p COMPLEX

SOSA LILIANA DEL VALLE; PASTRANA RIOS BELINDA

San Juan, Puerto Rico

Conferencia; UPR-Protein Research Center Spring Conference,; 2006

National Institutes of Health?s Centers of Biomedical Research Excellence (NIH-COBRE II) program and the University of Puerto Rico.

Chlamydomonas centrin is an acidic, low molecular weight protein that belongs to the EF-hand superfamily of calcium binding proteins. It is an essential component of the centrosomal structures in the wide range of organisms. Centrin and its binding protein Sfi1p act as contractile or elastic connections between centrioles and basal bodies. Sfi1p protein contains multiple internal repeats, with each repeat binding one centrin molecule. Transition temperature upon complex formation between Chlamydomonas 13C-labeled centrin and Sfi1p, one domain, were studied in aqueous D2O solution as a function of temperature using Fourier transform-infrared (FT-IR) spectroscopy and two-dimensional correlation analysis (2DCOS). The use of isotope labeling can applied in a protein and thus probes the changes that occur in presence the peptide. Spectral features studied in the spectral region amide I (17O0-1550 cm-1) were characteristic of the protein complex. Therefore, the relative thermal stability for these proteins was established.