Volumetric and viscometric behaviour of soya bean and gram proteins in aqueous methotrexate (anticancer drug) solution at 298.15 to 308.15K

Apparent molar volumes (V f ) and viscosities (h) for 0.00005 to 0.0004 kg.mol-1 (50 to 400 mmol kg-1) aqueous methotrexate (MT X ), gram (Gp) and soya bean (SBp) proteins, and similar compositions of Gp and SBp each in 50 to 400 mmol kg-1 aqueous MT X were determined at 298.15, 303.15 and 308.15K. The V f values are positive except aqueous MT X and listed as SBp > Gp > MTX in aqueous and SBp > Gp in MTX solutions, respectively. It infers weaker hydrophobic heteromolecular interaction of SBp in binary and ternary systems. The higher h values of SBp and Gp in MT X than those of aqueous MT X prove strengthening of hydrophobic interactions of proteins by MT X . It illustrates the conformational changes of proteins; slightly higher V f values of SBp than of Gp. The MTX confirm higher structural activity in biological process. The V f 0 of MT X increases with K and decrease with composition. But with compositions the values continuously decrease with lower magnitude.