Purification and characterization of vigna unguiculata cultiver asparaginase

Asparaginase [EC 3.5.1.1] activity was determined in non germinating seeds and germinating seeds of five Egyptian cowpea [Vigna unguiculatd] cultivars [Kareem 7, Dokki 331, Kafer El-Sheikh 1, Kaha 1 and Fodder]. The specific activities of germinating seeds asparaginase in different cultivars were higher than the specific activities of non germinated seeds of these cultivars. Asparaginase was purified from Fodder cultivar germinating seeds [the highest specific activity] and resolved into three peaks with asparaginase activities by DEAE sepharose, designated by asp I, asp II and asp III. The molecular weight of asp II was 70 kDa for native enzyme using gel filtration. By using SDS-PAGE electrophoresis, asp II had molecular weight about 35 kDa suggesting that a dimeric structure for asp II. AspII had a Km value 1.25 mM for asparagine and a pH optimum at 8.0. Asp II had a temperature optimum and heat stability at 40 °C. The fodder cultivar asp II activity was specific for L-asparagine and did not hydrolyze D-asparagine. It is not specific for L-glutamine. Ni[2+] and Co[2+] had activator effects on asp II but other metals ions had inhibitory effect

Nitric oxide as a marker for diagnosis and follow-up in children with systemic lupus erythematosus and juvenile rheumatoid arthritis

A cross sectional observational study of 56 children with juvenile rheumatoid arthritis [JRA] and systemic lupus erythematosus [SLE] was designed to study nitric oxide [NO] levels and their relation to the disease activity and its value as an indicator for the follow up of these two diseases. Twenty-five healthy age and sex matched children were recruited as controls. Full history taking, proper clinical examination and laboratory investigation of the subjects were done. Blood samples were collected and NO, nitrite and nitrate were measured biochemically. Serum NO, nitrite and nitrate were significantly higher in each of JRA and SLE cases compared with the control group. Patients with active disease showed higher NO levels compared with non-active disease, yet it did not reach significant levels. A positive significant correlation was observed between NO and erythrocyte sedimentation rate [ESR] for patients with active SLE and JRA, respectively. A negative significant correlation was found between NO and lymphocyte count in active SLE; while, a positive significant correlation between NO and steroid therapy duration of JRA with active disease was observed