Polyphosphate (poly-P) Exopolysaccharides (EPS) • Autoinducers (AI) • Guanidine tetraphosphate (ppGpp) The lab came back with the following results for the following patients: Marco C-di-GMP Poly-P EPS Al (p)ppGpp Control S.aureus P.aeruginosa + +++ + ++++ ++ + ++ +++ ++ ++ +++ Alexandre C-di-GMP Poly-P EPS Al (p)ppGpp Control S.aureus + + ++++ ++ ++++ P.aeruginosa n/a n/a n/a n/a n/a Dr Moochin is aware that P.aeruginosa possesses a TA system which promotes virulence and help the bacterial population to resist antibiotic treatment. The P.aeruginosa Toxin/Antitoxin (TA) system leads to the activation of an RNASE (a different system then the HipAB system seen in class). The end results are similar tough, when activated, this P.aeruginosa TA system leads to cell dormancy. Thinking about what you know of the mechanisms that lead to cell dormancy and persistence, how could the activation of an RNAse by the P.aeruginosa TA system have a similar effect then that of the HipAB system? Explain your reasoning.

2. The following tyrosine-phosphorylated polypeptides were tested as substrates of protein tyrosine phosphatase, an important enzyme in cellular signal transduction. The pTyr in bold signifies the tyrosine residue that is phosphorylated. The binding affinities of the polypeptide substrates to the enzyme were found to follow the order: (a) > (c) - (d) >> (b). (a) Asp-Ala-Asp-Glu-pTyr-Leu-lle-Pro-Gln-Gln-Gly (b) Pro-Val-Pro-Glu-pTyr-lle-Asn-Ala-Ser-Val (c) Asp-Ala-Glu-Glu-pTyr-Leu-Val-Pro-Gln-Gln-Gly (d) Asp-Asn-Leu-Tyr-pTyr-Trp-Asp-Glu-Asn-Ser-Ser In addition to the presence of the phosphorylated tyrosine residue, what amino acid a) properties of the polypeptides accounts for the relative order of binding affinities to the enzyme? b) the active site of the phosphatase enzyme that are responsible for the affinity of substrate binding? Assume a pH of 7.4 at the enzyme active site. (Note a phosphatase uses phosphate substrate) What amino acids have side chains that would indicate they are…

Tetrodotoxin  identify the species which releases the toxin (if it is man-made then this will be all that is required for this part) identify the step disrupted in the neuromuscular junction pathway Provide any consequences of this disruption.   Does the toxin have any applications in biomedicine as a painkiller, disease treatment or analgesic? Provide your source in APA format for each.  If this is missing no credit will be awarded.

A chain NH3 NH3 B chain Gly Phe 2. The protein pictured below is bovine insulin. Determine the number and the size of the fragments that would be generated upon treatment with the following: İle Val Val Asn Gln Gln 5 Ġln 5 His look for the cleavage points (a) without DTT and (b) with DTT. Cys Leu Cys S-S Cys Without DTT With DTT Ala Ģly Ser Ser Trypsin 10 Val 10 His Cys Leu Chymotrypsin Ser Val Leu Glu BrCN Tyr Ala 15 Gln 15 Leu Leu Тyr Ġlu Leu Ásn Val Тyr Cys 20 Çys 20 Gly Asn Glu Arg Reagent (source) Trypsin (bovine pancrease) Chymotrypsin (bovine pancrease) Staphylococcus V8 protease Pepsin (porcine pancrease) Cyanogen bromide (chemical)(CnBr) Specificity Lys, Arg (C) Phe, Trp, Tyr (C) Glu, Asp (C) Phe, Trp, Tyr (N) Met (C) Gly Phe 25 Phe Тyr Thr Pro Lys 30 Ála