Spectroscopic characterization of gelonin--assignments secondary structure and thermal denaturation.

Gelonin, a type 1 ribosome inactivating protein (RIP), having only one polypeptide chain, and which could be used against deadly diseases like cancer and AIDS is investigated spectroscopically through infrared (IR), diffused reflectance infrared fourier transform (DRIFT) and Raman techniques and observed vibrational modes are assigned. It is found that gelonin is having mainly alpha-helix and beta-sheet structure with some turn and disordered structure, the estimated percentage structure using Raman data being approximately 32% alpha-helix, approximately 20% beta-sheet, approximately 26% turn and approximately 22% disorder type. The temperature dependent infrared study of gelonin reveals its thermal stability, the denaturation temperature being around 60 degrees C and disordered contribution increasing with heating.

Possible role of mononuclear phagocytes in clearance of immune complexes in pulmonary tuberculosis.

Phagocytic activity of peripheral blood mononuclear cells (PBMC) was investigated in 30 patients with pulmonary tuberculosis. The test was done using neutral red. Higher percentages of phagocytic cells were detected with PBMC of tuberculosis patients as compared with controls. An inverse relationship was observed between neutral red positive cell counts vs. relative percentages of several proteins (IgG, C3 and C4) in PEG precipitates in tuberculosis patients. It was interpreted that phagocytes might have mopped up the CICs via their surface Fc receptors.