There are many plants in Kashmir valley which have been shown to possess medicinal properties. Among them is Euphorbia helioscopia which is known for its medicinal values. At present drug resistance is a worldwide problem and much emphasis is being laid on the natural plant sources to act as antibiotics which can overcome this problem. Euphorbia helioscopia which is known for its medicinal values has febrifuge and vermifuge activities in its roots and stem respectively. The root is anti helminthic. The milky sap is applied externally to skin eruptions. The seeds, mixed with roasted pepper, have been used in the treatment of cholera and the oil from the seeds has purgative properties. However, isolation of any antibacterial protein has not been reported till date. The essence of the work was to check the antibacterial activity of the plant following its purification and characterization from leaves using conventional protein purification techniques. The lectin is a homodimer (Mr 65000Da), thermostable between 0 C- 40 C but exhibits a narrow range of pH stability being optimally active at pH 7. The lectin shows antimicrobial activity against P. aeruginosa, K.pneumoniae and E. coli.

Lectins are carbohydrate-binding proteins of non-immune origin that agglutinate cells or precipitate glycoconjugates.Based on evolutionary and structural relatedness, seven lectin families have been distinguished, of which legume lectins are the best characterized. Lectins typically constitute a large fraction of the total protein in most leguminous seeds and plant storage tissues where they play an important role in several defense mechanisms. A lectin from the seeds of Indigofera heterantha, member of family leguminosae was isolated, purified, partially characterized and its antimicrobial activity evaluated. The lectin is a homotetramer with a molecular weight of about 70 KDa. The lectin shows a reasonable temperature stability and is stable in the pH range of 2-9. It demonstrates a remarkable antibacterial activity against E.coli, K.pneumonia, S.aureus, and B.subtilis and also inhibits the growth of phytopathogens Aspergillis niger, Aspergillis oryzie and Fusarium oxysporum. These results point out that future findings on applications of lectins isolated from leguminous plants can be of great importance for clinical microbiology and possible therapeutic applications.

-galactosidases belong to glycosyl hydrolase family of enzymes.These enzymes are widely distributed in nature. -galactosidases have been implicated in many biological functions like hydrolysis of dietary lactose, degradation of glycolipids and proteoglycans, fruit ripening, cell elongation, storage mobilisation and petal senescence. - galactosidase has proven as a best alternative for elimination of lactose intolerance.The present study was aimed at investigating the biochemical properties of -galactosidases from apricots.Three isoenzymes( -gal I, -gal II and -gal III) were obtained by salt fractionation and ion-exchange and Sephadex G-100 column chromatography. -gal I, II and III showed 0.39, 0.52 and 0.30 units of activity respectively. The molecular weight of -gal I, II an III as determined by gel filtration was found to be 44.15,34.70 and 23.71 KDa respectively. The optimum pH for the activity of different isozymes was between 4 and 6. The isoenzymes were determined to be thermally stable upto 40oC. The Km for -gal I was 1.85mM,1.7mM for -gal II and 1.19 for -gal III.The Vmax for -gal I, -gal II aand -gal III was found to be 0.52,0.70 and 0.38umole/min respectively.

Lectins are proteins or glycoproteins of non immune origin which have a wide distribution in animals, plants, and microorganisms. Their medicinal role extends from simple antimicrobial action to anti- tumour properties.In view of the advancement in understanding the potential medicinal role of the plant lectins, a lectin from the leaves of Prunella vulgaris was isolated, purified, partially characterized and its antimicrobial activity evaluated. The lectin is specific for galactose and N-acetyl-galactosamine The molecular weight of the lectin as determined by SDS-PAGE was 32500 Da and that estimated from Sephadex G-100 gel filtration column was 65000 Da indicating that the purified lectin is a homodimer. The purified lectin also shows a significant antimicrobial activity against the infectious agents of some common diseases such as Salmonella typhi, Klebseilla pnuemonea and Escherhia coli.

Plant lectins are a heterogeneous group of proteins or glycoproteins that share in common their ability to recognize and bind specific sugar residues. At present hundreds of plant lectins have been isolated and characterized with respect to their molecular structures and carbohydrate-binding specificities. Since the unique biological properties of lectins can be exploited in the investigation of numerous biochemical and cellular phenomena, intense efforts are being made in many labs to isolate lectins with unique and unusual sugar-binding specificities. The study deals with the purification and partial characterization of a lectin from Crotalaria pallida belonging to Leguminoseae. Conformational changes and changes in biological properties by chemical modification of the lectin are also a part of the study. The lectin is a monomeric galactose and blood group A specific glycoprotein with about 4% carbohydrate and a molecular weight of 43 kDa. The activity yield of the lectin was about 4.6% with nearly three fold purification. Conformational changes were investigated by gel filtration, viscometery and UV absorption spectroscopy.

Zea mays (a C4 plant) can withstand high sulfur dioxide concentrations up to 12.0 ppm without any harmful effects. Visible injury symptoms appear only after exposure to sulfur dioxide concentrations beyond 12.0 ppm. The pigments, proteins, amino acids and starch decrease after exposure to higher concentrations of sulfur dioxide. The free sugars, however, increase in response to sulfur dioxide exposure. The activity of PEP - carboxylase is inhibited non -competitively with respect to substrates, PEP and Mg2+ but it is competitive with HCO3-.The high affinity of the enzyme for HCO3- renders the replacement by sulfur dioxide more difficult which results in decreased sensitivity towards sulfur dioxide. NADP - malate dehydrogenase is inhibited uncompetitively with respect to OAA and non - competitively with respect to NADPH. The low inhibitory effect of sulfur dioxide on the enzymes is indicated by high Ki values.In case of NADP - malic enzyme, sulfur dioxide shows a non - competitive inhibition with respect to NADP+ but a competitive one with respect to Mg2+. With respect to malate, the inhibition is partially competitive.