The QPT gene codes for the QPTase (enzyme), which is found in both prokaryotes and eukaryotes. The enzyme provides the only route for QA metabolism and is essential in the de novo biosynthesis of NAD. It catalyzes the reaction between QA and 5-phosphoribosyl 1-pyrophosphate (PRPP) in the presence of Mg2+ ions which results in the production of nicotinic acid mononucleotide (NAMN), inorganic pyrophosphate and carbon dioxide. QPTase plays a vital role in the regulation of the pyridine nucleotide cycle. This cycle is essential for the production of NAD, which is a co-enzyme involved in the oxidation reaction for metabolism in all organisms. In the Nicotiana species, this enzyme ensures the presence of adequate nicotinic acid for the synthesis of pyridine alkaloids. (Eads et al., 1997; Cane et al., 2005).
Previous studies by Zhang and Baldwin, 1997 found that alkaloid levels soared over several days after the above ground tissues of Nicotiana plants were wounded by herbivores. It was discovered that this was due to an increase in the rate of de novo nicotine synthesis in roots, which was initiated by the release of the hormone methyl jasmonate, which activates and up-regulates the QPT gene and eventually producing nicotine as a gene product of translation. Nicotine is then transported to the aerial foliage over the following days as a defensive substance against herbivores and parasites. It affects the nervous system by blocking the transmission of neurotransmitters at the neuromuscular junction and autonomic ganglia resulting in nervous system breakdown and subsequent respiratory failure, leading to death (De Boer, 2011; Ruiz et al., 2005).
[...] Isolation and identification of egg white proteins using biochemical techniques INTRODUCTION Human beings need a balanced diet of carbohydrates, proteins, fats and numerous other nutrients. Proteins are needed as part of a healthy balanced diet in order to sustain growth, provide structural support, boost the defences of the body and are involved in many vital body functions. Among the various sources of protein, one commonly consumed, rich source of such proteins is the eggs of the domestic fowl. The eggs of the domestic fowl consist of the egg white (albumen) and egg yolk. [...]
[...] This was observed in Figure 5 for the CaMV35S promoter in roots and for the NQPT2 promoter in leaves. However, the opposite was observed in CaMV35S promoter in leaves and for the NQPT2 promoter in roots as the wounded sample showed a slightly lower or nearly equal GUS activity than the non-wounded in roots and nearly halved GUS activity in leaves on wounding. This means that wounding of aerial tissue increased expression of GUS in roots when the CaMV35S promoter was present and in leaves in the presence of the NQPT2 promoter. [...]
[...] It affects the nervous system by blocking the transmission of neurotransmitters at the neuromuscular junction and autonomic ganglia resulting in nervous system breakdown and subsequent respiratory failure, leading to death (De Boer, 2011; Ruiz et al., 2005). Possible fate of a duplicated gene There are three probable fates for a duplicated gene. The first fate is that of a pseudo-gene which is an inactivated and hence, non-functional duplicated gene. Loss of function of this gene is caused by accumulation of many genes which undergo a series of deleterious mutations. [...]
[...] However, the NQPT2 gene was deduced to be non-functional as promoter in roots, as GUS was not produced in any of the plant species tested. Also it was found that the NQPT2 promoter had stronger promoter ability than CaMV35S but CaMV35S is ideal for steadily increasing GUS gene expression in roots as a defensive mechanism when wounded. Bibliography Akhtar S., Briddon R.W. and Mansoor S. (2011). Reactions of Nicotiana species to inoculation with monopartite and bipartite begomoviruses. Virology Journal 475. [...]
[...] Only a small amount of iron 5.82 10-5 g was required to fully saturate the protein in the solutions prepared in tubes 2 -10. Furthermore, the calculations show that the iron binding capacity of conalbumin is very high as 1 mole of conalbumin binds to 2.635 moles of iron which is a large amount of iron that conalbumin binds to. CONCLUSION Ovalbumin was found to have the highest amount of protein as compared to lysozyme and conalbumin. The specific activity and total activity showed that lysozyme D was the most effective enzyme to catalyse reactions of reducing bacterial activity and then lysozyme A and then lysozyme C and lastly lysozyme B. [...]
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