Site-directed mutagenesis replaces a specific amino acid in a protein with a different amino acid, and this approach is commonly used by biochemists to determine if an amino acid is essential for a protein’s function and probe that residue’s role in that function. Which of each pair of amino acid substitutions listed below would you expect to disrupt protein structure the most? Explain. a. Gln replaced by Glu or Asn b. Lys replaced with Asp or Arg c. Thr replaced by Val or Phe d. Pro replaced with His or Gly
Option d) is the correct option. When proline is replaced by histidine or glycine, the protein structure is disrupted the most because proline has a xomplex rigid ring structure that confers a steric hindrance to neighbouring atoms such that they can acquire only limited conformations, however when it is replaced by glycine which has the simplest side chain or histidine, steric hindrande is not as strong and the polypeptide can acquire a number of conformations due to increased flexibility.
Site-directed mutagenesis replaces a specific amino acid in a protein with a different amino acid, and...
1. You are performing mutagenesis to test predictions about which residues are essential for a protein's function. Which of the each pair of amino acid substitutions listed below would you expect to disrupt protein structure most and WHY? Val replaced by F or A Lys replaced by Asp or R Gln replaced by Glu or Asn Pro replaced by His or Gly
Table 1: Partial RPE65 protein sequence (amino acids 41-60) for the 9-year-old LCA patient. Unmutated Protein Sequence Patient's Allele 1 Protein Sequence Patient's Allele 2 Protein Sequence START...Ser-Leu-Leu-Arg-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP START...Ser-Leu-Leu-Gin-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP START...Ser-Leu-Leu-Gin-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP Table 2. Partial RPE65 protein sequence (amino acids 61-70 and 291–300) for the 11-year-old LCA patient. Unmutated Protein Sequence Patient's Allele 1 Protein Sequence Patient's Allele 2 Protein Sequence START...Phe-Asp-Gly-Gln-Ala-Leu-Leu-His-Lys-Phe...lle-Ala-Asp-Lys-Lys-Arg-Lys-Lys- Tyr-Leu...STOP START...Phe-Asp-Gly-Gln-Ala-Leu-Leu-Tyr-Lys-Phe...lle-Ala-Asp-Lys-Lys-Arg-Lys-Lys- Tyr-Leu...STOP START...Phe-Asp-Gly-Gln-Ala-Leu-Leu-His-Lys-Phe...lle-Ala-Asp-Lys-STOP Source: Data from Russell et al. (2017). Use Tables 1 and 2 to...
What amino acid would the Manticodon code for RNA codon table 2nd position Tot position СТА Tyr Phe Phe > eu eu Oulaa Jooo 9999 stop stop eu eu eu Let 0 - puchbucobucusura BER < Val Val Asp Ala Asp Ala Glu Ala Glu Amino Acids Keu Pro Pro His Weu Leu Gin lle Pro Thr Thr Thr Thr Asn Asn lle Ser Ser Arg lle Met Lys Lys bucoucouco Arg > Asp Asp Val Val Val Val Ala...
On your internship, you visit the Mass Spectrometry Lab. Mass spectrometry can identify short peptide fragments based on their molecular weights. Your fellow intern Jerry has neglected to label his tubes of amyloid beta peptide 42 after digesting them with some proteases that we learned about in Module 6: pepsin, trypsin, and chymotrypsin. Help him figure out what protease is in each tube. Jerry’s supervisor has the fragments listed in the same order as the original peptide primary sequence, which...
repulsion within the protein 10. Which of the following amino acids do not contain a chiral carbon? a. Proline b. Alanine c. Glycine d. Phenylalanine e. Tyrosine 11. You want to determine an amino acid sequence for a particular polypeptide. So you degrade the peptid and get the following fragments. Determine the peptide sequence. Digested with typsin: Met-Val-Ser-Thr-Lys Val-lle-Trp-Thr-Leu-Met-lle Leu-Phe-Asn-Glu-Ser-Arg Digested with chymotrypsin: Asn-Glu-Ser-Arg-Val-lle-Trp Thr-Leu-Met-lle Met-Val-Ser-Thr-Lys-Leu-Phe a. Val-lle-Trp-Thr-Leu-Met-lle-Leu-Phe-Asn-Glu-Ser-Arg-Met-Val-Ser-Thr-Lys b. Val-lle-Trp-Thr-Leu-Met-lle-Met-Val-Ser-Thr-Lys-Leu-Phe-Asn-Glu-Ser-Arg c. Leu-Phe-Asn-Glu-Ser-Arg-Met-Val-Ser-Thr-Lys-Val-lle-Trp-Thr-Leu-Met-le d. Met-Val-Ser-Thr-Lys-Leu-Phe-Asn-Glu-Ser-Arg-Val-le-Trp-Thr-Leu-Met-lle e. Met-Val-Ser-Thr-Lys-Val-lle-Trp-Thr-Leu-Met-lle-Leu-Phe-Asn-Glu-Ser-Arg
Suppose part of the amino acid sequence of a protein is N... Gly
- Ala - Pro - Arg - Lys ...C. Which of the following amino acid
sequences could result from a frameshift mutation (+1 or -1) in the
part of the gene that encodes this sequence of amino acids?
Ο N... Gly - Ala - Asn - Ser - Leu ...C Ο Ν...Αla - Ala - Arg - Pro - Lys...C Ο Ν...Gly - Gly - Thr -...
3. A protein contains the following amino acids: O ALA 4 GLN 1 LEU 3 ARG 4 GLU 4 LYS 4 ASN 5 GLY O MET 1 ASP 1 HIS 2 PHE 4 ILE 4 PRO 8 SER 5 THR 1 TRP 2 TYR 2 VAL BGYS. a) What is its net charge at pH 1? b) What is its net charge at PH 13? c) Calculate the pl. 4. In what order would the amino acids GLU, LYS, and...
Table 1: Partial RPE65 protein sequence (amino acids 41-60) for the 9-year-old LCA patient. Unmutated Protein Sequence Patient's Allele 1 Protein Sequence Patient's Allele 2 Protein Sequence START...Ser-Leu-Leu-Arg-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP START...Ser-Leu-Leu-Gin-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP START...Ser-Leu-Leu-Gin-Cyc-Gly-Pro-Gly-Leu-Phe-Glu-Val-Gly-Ser-Glu-Pro-Phe-Tyr- His-Gly...STOP Table 2. Partial RPE65 protein sequence (amino acids 61-70 and 291-300) for the 11-year-old LCA patient. Unmutated Protein Sequence Patient's Allele 1 Protein Sequence Patient's Allele 2 Protein Sequence START...Phe-Asp-Gly-Gln-Ala-Leu-Leu-His-Lys-Phe...lle-Ala-Asp-Lys-Lys-Arg-Lys-Lys- Tyr-Leu...STOP START...Phe-Asp-Gly-In-Ala-Leu-Leu-Tyr-Lys-Phe...Ile-Ala-Asp-Lys-Lys-Arg-Lys-Lys- Tyr-Leu...STOP START...Phe-Asp-Gly-Gln-Ala-Leu-Leu-His-Lys-Phe...lle-Ala-Asp-Lys-STOP Source: Data from Russell et al. (2017). Use Tables 1 and 2 to...
How many amino acids are there in the disease causing variant of
the Amyloid-beta (Ab) peptide?
Determine which of these four peptides is most likely to become a beta sheet. Lys-Thr-Val-Ile-Trp-Pro-Phe-Tyr-Ile-Gln-Ile-Gly Arg-Ser-Tyr-Glu-Gly-Leu-Lys-Arg-Ile-Ala-Glu-Ser Ala-Glu-Met-Leu-Gln-Lys-Arg-Gly-Cys-Gly-Asp-Glu Met-Leu-Lys-Ala-Ser-Ala-Leu-Glu-Lys-Leu-Ser-Glu
PLEASE HELP OCHEM QUESTION
1. In the following protein, identify the type of bonding or interaction that is responsible for holding the two peptide chains together at each amino acid pair, above (A) and below (B). Gly - Ala - Ser - Cys - Val - Asp - Leu - Thr - His - Ile-Tyr-Glu - Phe - Lys - Cys - Met - Asn Val - Leu -Gin-Cys - Pro-Lys - Met - Tyr - Asp -Phe-Asn-Lys - Ile...