Fun Biology Problem
In the Aliens franchise, the catalyst A0-3959X.91 – 15 is an extreme mutagen that causes the destruction and reformation of DNA. In the franchise, A0-3959X.91 – 15 was created by a species called the Engineers, who used A0-3959X.91 – 15 to create life on Earth. An interplanetary mission from Earth to the Engineer homeworld resulted in scientists recovering a sample of A0-3959X.91 – 15 for analysis in the laboratory. It was subsequently discovered that A0-3959X.91 – 15 was composed of organic nanomachines that bind to the DNA backbone to cleave and degrade it. The scientists investigating the mechanism of A0-3959X.91 – 15 reported that it could also inhibit many other enzymes in a solution of pH = 7.0. A Lineweaver-Burk Plot for one of these enzymes, denoted as Enzyme X, is displayed below. The green line represents Enzyme X + A0-3959X.91 – 15, and the red line represents Enzyme X without any inhibitor.
Which of the following would be most true of A0-3959X.91 – 15 and Enzyme X?
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1 solution
Answer: Choice B - Enzyme X might have Aspartate in its Active Site
Choice A: this is wrong because the slope of the Lineweaver-Burk Plot increases, meaning that the affinity with the Active Site of Enzyme X is reduced upon treatment with A0-3959X.91 – 15. In other words, A0-3959X.91 – 15 is a competitive inhibitor for Enzyme X. An Allosteric inhibitor does NOT bind to the Active Site.
Choice B: this is correct because A0-3959X.91 – 15 would bind to the Active Site of Enzyme X. Since A0-3959X.91 – 15 cleaves the DNA Backbone, it interacts with Phosphates on the DNA backbone, meaning A0-3959X.91 – 15 is positively charged. Thus, the Active Site of Enzyme X is negatively charged, so any negatively charged Amino Acids such as Glutamate or Aspartate would be likely to be found.
Choice C: this is wrong because the slope of the Lineweaver-Burk Plot increases, meaning the affinity of Enzyme X with its Substrate would be reduced.
Choice D: this is wrong because there is no data that supports the idea that Enzyme X has multiple subunits undergoing cooperativity.
Choice E: this is wrong because “chaotropic” means A0-3959X.91 – 15 disrupts Hydrogen Bonds, but since A0-3959X.91 – 15 binds and cleaves on the DNA backbone, the main mechanism that A0-3959X.91 – 15 would use is cleaving the covalent bonds, instead of disrupting Hydrogen Bonds between the DNA Nitrogenous Bases.