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Title: Effects of sodium dodecyl sulphate on enhancement of lipoxygenase activity of hemoglobin Authors: Ezebuo, F C Eze, S O O Chilaka, F C Keywords: Hemoglobin Linoleic acid Lipoxygenase Met-hemoglobin Oxodienes Sodium dodecyl sulphate Issue Date: Dec-2012 Publisher: NISCAIR-CSIR, India Abstract: Lipoxygenases comprise a family of non-heme iron-containing enzymes that catalyze the stereospecific dioxygenation of polyunsaturated fatty acids with 1, 4-cis-cis-pentadiene structure. Hemoglobin, a heme iron-containing protein has been reported to have lipoxygenase activity but the assay conditions that could enhance the activity remain obscure. Therefore, establishment of optimum assay conditions for lipoxygenase activity of hemoglobin could allow modeling of hemoglobin as lipoxygenase. Hemoglobin was extracted from blood of an identified individual of genotype AA. The hemoglobin was dialyzed at 4 oC for 24 h against 50 mM Tris-HCl buffers (pH 8.5 and 7.2) and effects of sodium dodecyl sulphate (SDS) and linoleic studied at pH 5.0 and 7.2 with UV–VIS Titration Spectrophotometry. The results show that 3.3, 8.6 and 88.1% concentrations of met-hemoglobin were found in presence of 0.0 mM SDS at pH 5.0 and 7.2, 1.043 mM SDS at pH 7.2 and 0.404 mM SDS at pH 5.0 respectively. Also, the difference spectra of hemoglobin in presence of linoleic acid showed positive peak at 285 nm which suggest the presence of oxodienes–a reaction product of hydroperoxidase activity of lipoxygenase. Formation of met-hemoglobin/met-myoglobin is highly correlated with lipid oxidation. Since highest concentration of met-hemoglobin (88.1%) was observed in presence of 0.404 mM SDS at pH 5.0, lipoxygenase activity of hemoglobin was enhanced in presence of SDS under these conditions.
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Introduction: Alterations of serum lipid profiles have been reported widely among Human Immuno deficiency Virus (HIV) positive patients on Highly Active Anti Retroviral Therapy (HAART). However; there are few data on serum lipid profile among treatment na?ve HIV positive patients in our environment. Objectives: To describe the pattern of lipid profile among treatment na?ve HIV positive patients and changes following HAART initiation. Methods: One hundred and thirty HIV positive patients seen in HIV center in an urban area in Nigeria and 44 matched individuals were recruited. Data were collected on socio demographic characters; baseline lipid profiles and CD4 count. Values of lipid parameters were retrieved after 12 months on HAART. Results: The mean Low density lipoprotein(LDL) was 2.26+ 0.9 mmol/l among the test group compared with 0.96+0.39mmol/L among the control ;p value =0.000 .The mean High density lipoprotein (HDL) was also significantly lower;0.8+ 0.6mmol/L reaching a dyslipidemic level; in the HIV positive group than the control; p value = 0.00. Tuberculosis /HIV co infected patients had a significantly elevated mean LDL; p=0.002. Conclusion: Abnormality of serum lipid is common among treatment na?ve HIV patients seen in Nigeria. The NNRTI regimen is associated with elevation of HDL and some stabilization of TC and TG