title: A study of inhibition of urease from seeds of the water melon (Citrullus vulgaris).
abstract: Urease from seeds of the water melon was found to be inhibited by various salts of sodium. Sodium fluoride strongly inhibited the activity in the low urea concentration range. The enzyme was also inhibited by a high concentration of urea which was completely abolished in the presence of 10 mM sodium fluoride. Time-dependent inactivation of urease with iodoacetic acid, N-ethylmaleimide and p-hydroxymercuribenzoate exhibited biphasic kinetics in which half of the initial activity was lost in the fast phase and the remainder in a slow phase. Each phase exhibited first-order kinetics. These observations are suggestive of the existence of half-and-half distribution of sites.
authors.affiliation: Department of Biochemistry, Faculty of Science, Banaras Hindu University, Varanasi, India.
authors.forename: O
authors.initials: O
authors.lastname: Prakash
authors.forename: G
authors.initials: G
authors.lastname: Bhushan
mesh_terms: D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology; D005638:Fruit / Q000201:enzymology*; D006902:Hydroxymercuribenzoates / Q000494:pharmacology; D019807:Iodoacetic Acid / Q000494:pharmacology; D007700:Kinetics; D012492:Salts / Q000494:pharmacology; D012639:Seeds / Q000201:enzymology; D017670:Sodium Compounds / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014510:Urease / Q000037:antagonists & inhibitors*
chemical_list: D004791:Enzyme Inhibitors; D006902:Hydroxymercuribenzoates; D012492:Salts; D017670:Sodium Compounds; D013439:Sulfhydryl Reagents; C030601:4-hydroxymercuribenzoate; D012969:Sodium Fluoride; D014510:Urease; D005033:Ethylmaleimide; D019807:Iodoacetic Acid