7 research outputs found
Effect of Different Steeping Conditions on the Peroxidase Activities of Some Improved Sorghum Varieties
In order to evaluate the impact of duration and the incorporation or otherwise of air rest during steeping on the peroxidase activities of sorghum grains, five improved varieties were studied. Steeping durations used ranged from 0 (raw grains) to 72 hours, in two formats: with air rest and without air rest. Results obtained showed that among the raw grains which were the control experiment, variety SK5912 gave the highest peroxidase activity, followed by variety KSV 8 while variety CSRO2 had the least peroxidase activity. During steeping, we observed that in almost all cases, higher peroxidase activities were obtained with air rested sorghum grains than those without air rest. In terms of how the different varieties compared during steeping, we found that variety KSV 8 gave the highest peroxidase activity at both with and without air rest regimes in all the steeping periods used. Also, we observed that in all cases, the highest increase in peroxidase expression was obtained during the first 6 hours of steeping, shown by a steep rise of over 50% increase in activity. The other steeping times following the first 6 hours however showed just gradual increases in peroxidase over the period of sorghum. The major significance of this result is that although increasing duration showed increased peroxidase activities, such increases were less jumpy than those obtained during the first 6 hours. Therefore, long steeping times may not necessarily be very beneficial, with the added benefit that costs associated with long steeping durations may be avoided.Key words: Sorghum, cereals, peroxidases, enzymes, steeping, germination, air rest
Structural and spectroscopic characterisation of a heme peroxidase from sorghum
A cationic class III peroxidase from Sorghum bicolor was purified to homogeneity. The enzyme contains a high-spin heme, as evidenced by UV-visible spectroscopy and EPR. Steady state oxidation of guaiacol was demonstrated and the enzyme was shown to have higher activity in the presence of calcium ions. A Fe(III)/Fe(II) reduction potential of -266 mV vs NHE was determined. Stopped-flow experiments with H2O2 showed formation of a typical peroxidase Compound I species, which converts to Compound II in the presence of calcium. A crystal structure of the enzyme is reported, the first for a sorghum peroxidase. The structure reveals an active site that is analogous to those for other class I heme peroxidase, and a substrate binding site (assigned as arising from binding of indole-3-acetic acid) at the Îł-heme edge. Metal binding sites are observed in the structure on the distal (assigned as a Na(+) ion) and proximal (assigned as a Ca(2+)) sides of the heme, which is consistent with the Ca(2+)-dependence of the steady state and pre-steady state kinetics. It is probably the case that the structural integrity (and, thus, the catalytic activity) of the sorghum enzyme is dependent on metal ion incorporation at these positions
Purification and Characterization of a Novel p,p\u2019-DDT Dehalogenase from Aeromonas sp. strain MY1
Although dichlorodiphenyltrichloroethane (DDT) occupies a prominent
position for its recalcitrance in the environment which led to its ban
by the Stockholm Convention. This pesticide is still unregulated used
in low and middle-income countries, which contributes to the global
burden of this hazardous contaminant. In the recent time, biological
approach has been proven to be effective and environmentally safer for
the decontamination of the residual DDT. In this research, we reported
a gel-purified p,p\u2019-DDT dehalogenase from Aeromonas sp. strain
MY1, revealing a single band with a molecular weight of approximately
37 kDa. The dehalogenase was unique for its capability to release
chloride ions from p,p\u2019-DDT substrate with optimum dechlorination
activity at pH 8.0 and 35\ub0C. The enzyme followed
Michaelis-Menten\u2019s kinetics and measurement of its initial
velocities with various p,p\u2019-DDT concentrations showed a Km of
27.05 \u3bcmol L-1 and Vmax of 476.19 \u3bcmol L-1 min-1. However,
the enzyme lost its dechlorination activity in the presence of Ag2+ and
Hg2+ This dehalogenase could pave a way for the effective
decontamination of p,p\u2019-DDT contaminated environment, suggesting
its potentials for p,p\u2019-DDT bio-cleansing applications
Prevalence of cardiovascular disease risk factors in a semi-urban Nigerian hypertensive population
The prevalence of high blood pressure and other associatedcardiovascular risk factors in a semi-urban Nigerian community werestudied. A total of 425 subjects aged 35 years and above took part in the cross sectional survey held at Nsukka, Nigeria. A detailed questionnaire was administered to the subjects to ascertain their risk levels consequent upon life style and genetic disposition. Anthropometric parameters, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured by standard methods. Fasting blood samples were drawn from the subjects for biochemical assays. Generally, hypertension prevalence [SBP > 140 mm Hg] was 74.77% in men and 68.59% in women. Men were more likely to be obese than the women. Stages II and III hypertension were more frequent in females while stage I hypertension was more frequent in males. The concurrence of hypertension, body mass index (BMI) and serum glucose were more likely in females while the simultaneous occurrence of BMI an
Lipid Composition Of Two Marine Fishes – Scomber scombrus And Trachurus trachurus
Lipids from two species of marine fish – Scomber scombrus and Trachurus trachurus were investigated. Fish oil from Trachurus trachurus had higher oil yield than that of Scomber scombrus. The lipids contain high levels of triacylglycerol 228 – 250 mg%, cholesterol 160 – 235 mg%, and phospholipids 2.2 – 2.4 mg%. Saponification of the different oils yielded saturated and unsaturated fatty acids, such as palmltic, oleic linoleic acids. Hexane and methanol were found effective solvents for separation of fatty acidsfrom the fish oil. Keywords: Fish oil, Nutrition, Industrial applications Animal Research International Vol. 1 (3) 2004 pp. 173-17