Fig. 6

Ras isoforms differ in their effector specificity and Ras isoforms exhibit a difference in symmetry in functional site surface roughness. a H-Ras, K-Ras and N-Ras specific siRNAs modulated the anti-CD40 antibody (3 μg/ml)-induced downstream Ras effector proteins Raf-1 and PI-3 K in P388D1 cells, as assessed by Western blot. siRNA treated P388D1 cells were stimulated with anti-CD40 antibody (3 μg/ml) for 10 min. b Analysis of association of H-Ras, K-Ras or N-Ras with PI3K or Raf in the co-immunoprecipitates from the lysates of anti-CD40 antibody (1 μg/ml and 6 μg/ml) treated macrophages for 10 mins. c The Correlation Dimensions (CD) were calculated to quantify the dependency in the spatial organization of surface atoms. CD magnitude varies within 2.00 and 3.00 for protein space. Results of this analysis too point unambiguously to similar organizational principles between dependencies (correlations) amongst surface atoms of H-Ras and K-Ras and their marked difference to that in N-Ras isoform. d Investigations were carried out on representative structures, viz., on pdb id.: 3K9L for H-Ras, pdb id.: 3GFT for K-Ras and pdb id.: 3CON for N-Ras. Extent of symmetry for all six aforementioned biophysical properties show that H-Ras and K-Ras molecules have a similar scheme of structural organization in interior and exterior of the molecule, which differs from that observed in N-Ras molecule. Such differences are significant because sequence identity between H-Ras, K-Ras and N-Ras molecules is found to be ≈ 89%.