Umamaheswara Rao

Learn More
The three-dimensional structure of alpha(1)-purothionin (alpha(1)-PT), a wheat-germ protein and a basic lytic toxin, was previously solved by molecular-replacement methods using an energy-minimized predicted model and refined to an R-factor of 21.6% [Teeter, Ma, Rao & Whitlow (1990). Proteins Struct. Funct. Genet. 8, 118-1321. Some deficiencies of the model(More)
We propose a molecular model for phospholipid membrane lysis by the ubiquitous plant toxins called thionins. Membrane lysis constitutes the first major effect exerted by these toxins that initiates a cascade of cytoplasmic events leading to cell death. X-ray crystallography, solution nuclear magnetic resonance (NMR) studies, small angle X-ray scattering and(More)
Alpha 1-Purothionin (alpha 1-P), a wheatgerm protein and lytic toxin, has a secondary and tertiary structure similar to that of crambin as revealed by CD and NMR studies. alpha 1-P crystallizes in the tetragonal space group 1422 with unit cell dimensions: a = b = 53.59 and c = 69.79 A. X-ray diffraction data have been measured to 2.5 A Bragg spacing. The(More)
The crystal structure of beta-purothionin (beta-PT) has been determined at 1.7 A resolution. beta-PT and previously solved alpha(l)-PT belong to a family of membrane-active plant toxins homologous to crambin. (beta-PT crystallizes in the same space group as alpha(l)-PT (1422) but with the c axis 3 A longer than (alpha(l)-PT. The unit-cell dimensions of(More)
Because of the problems in predicting a correct conformation for loop regions in homology-based prediction, disagreements are often found between the predicted models and the refined X-ray structures of the same protein in loop regions. Such a situation has been encountered for alpha 1-purothionin (alpha 1-PT). Hence, attempts have been made to improve the(More)
CD and fluorescence spectroscopic measurements show that calmodulin (CaM) binds to purothionins (alpha 1-purothionin: alpha 1-PT; beta-purothionin: beta-PT) in 1:1 stoichiometry with an affinity similar to that exhibited with the tightest binding CaM-binding peptides. Using the available crystal structures of CaM and alpha 1-PT, a model has been built for(More)
Titled compounds were prepared in a one-pot synthesis by generating symmetrically substituted benzyne intermediates by the diazotization of anthranilic acids in the presence of Barton esters. Unsymmetrically substituted aryne either gave mixtures of regioisomers or failed. However, nitro and methyl derivatives of titled compounds could be obtained as single(More)
The present work was attempted to study the Antibacterial activity and phytochemical analysis of Mangrove plant Avicennia alba. Leaf and stem extracts of A. alba were prepared in Hexane, Benzene, Chloroform, Ethyl acetate, Acetone and Methanol solvents. The resulted extracts of the plant were screened for antibacterial activity against Micrococcus luteus(More)
Background and objectives: Bacteria, most prevalently the Pseudomonas species possess high capacity to utilize and degrade petroleum hydrocarbons and are classified as the hydrocarbonoclastic microorganisms. Many species of the genus Pseudomonas are notorious for their aerobic degradation capacity, extracellular enzyme production and are metabolically(More)
  • 1