TABLE 5.1 Properties of the common amino acids found in proteins pK, of a-COOH Group pk, of a-NH Group pK, of lonizing Side Chain Abbreviations: 1- Residue Mass Occurrence in Name and 3-letter codes (daltons) Proteins (mol %) Alanine A, Ala 2.3 9.7 71.08 8.7 Arginine R, Arg 2.2 9.0 12.5 156.20 5.0 Asparagine N, Asn 2.0 8.8 114.11 4.2 D, Asp C, Cys Q, Gin E, Glu G, Gly Н, His I, lle Aspartic acid 2.1 9.8 3.9 115.09 5.9 Cysteine 1.8 10.8 8.3 103.14 1.3 Glutamine 2.2 9.1 128.14 3.7 Glutamic acid 2.2 9.7 4.2 129.12 6.6 Glycine 2.3 9.6 57.06 7.9 Histidine 1.8 9.2 6.0 137.15 2.4 Isoleucine 2.4 9.7 113.17 5.5 Leucine L, Leu 2.4 9.6 113.17 8.9 K, Lys М, Met F, Phe Lysine 2.2 9.0 10.0 128.18 5.5 Methionine 2.3 9.2 131.21 2.0 Phenylalanine 1.8 9.1 147.18 4.0 Proline P, Pro 2.0 10.6 97.12 4.7 Serine S, Ser 2.2 9.2 87.08 5.8 Threonine T, Thr 2.6 10.4 101.11 5.6 Tryptophan W, Trp 2.4 9.4 186.21 1.5 Tyrosine Y, Tyr 2.2 9.1 10.1 163.18 3.5 Valine V, Val 2.3 9.6 99.14 7.2

TABLE 5.1 Properties of the common amino acids found in proteins pK, of a-COOH Group pk, of a-NH Group pK, of lonizing Side Chain Abbreviations: 1- Residue Mass Occurrence in Name and 3-letter codes (daltons) Proteins (mol %) Alanine A, Ala 2.3 9.7 71.08 8.7 Arginine R, Arg 2.2 9.0 12.5 156.20 5.0 Asparagine N, Asn 2.0 8.8 114.11 4.2 D, Asp C, Cys Q, Gin E, Glu G, Gly Н, His I, lle Aspartic acid 2.1 9.8 3.9 115.09 5.9 Cysteine 1.8 10.8 8.3 103.14 1.3 Glutamine 2.2 9.1 128.14 3.7 Glutamic acid 2.2 9.7 4.2 129.12 6.6 Glycine 2.3 9.6 57.06 7.9 Histidine 1.8 9.2 6.0 137.15 2.4 Isoleucine 2.4 9.7 113.17 5.5 Leucine L, Leu 2.4 9.6 113.17 8.9 K, Lys М, Met F, Phe Lysine 2.2 9.0 10.0 128.18 5.5 Methionine 2.3 9.2 131.21 2.0 Phenylalanine 1.8 9.1 147.18 4.0 Proline P, Pro 2.0 10.6 97.12 4.7 Serine S, Ser 2.2 9.2 87.08 5.8 Threonine T, Thr 2.6 10.4 101.11 5.6 Tryptophan W, Trp 2.4 9.4 186.21 1.5 Tyrosine Y, Tyr 2.2 9.1 10.1 163.18 3.5 Valine V, Val 2.3 9.6 99.14 7.2

Organic Chemistry

9th Edition

ISBN:9781305080485

Author:John E. McMurry

Publisher:John E. McMurry

Chapter26: Biomolecules: Amino Acids, Peptides, And Proteins

Section26.SE: Something Extra

Problem 50AP: The -helical parts of myoglobin and other proteins stop whenever a proline residue is encountered in...

See similar textbooks

Similar questions

A 1.00-mg sample of a pure protein yielded on hydrolysis 0.0165 mg of leucine and 0.0248 mg of isoleucine. What is the minimum possible molar mass of the protein? (MMleucine=MMisoleucine=131g/mol)
What is the isoelectric point (pl) of arginine? Relevant amino acid structure is shown below: pka RCO2H/NH3*/other O 10.76 5.61 O 7.33 O 7.00 2.54 H3N-CH-C-OH CH₂ CH₂ CH₂ Please click here if image does not display correctly. 010 NH C=NH2 NH₂ Arginine Arg 2.17/9.04/12.48
Question 2. While internal cysteine amino acid sidechains in proteins undergo oxidation to produce disulfide crosslinks that stabilize the protein structure after folding, solvent-exposed cysteine sidechains can remain in their reduced thiol form and serve as reactive nucleophiles (recall for instance Acyl Carrier Proteins involved in fatty acid biosynthesis or various oxidoreductase enzymes). The reactive thiol groups in proteins can be detected using Ellman's test, wherein the protein is reacted with a disulfide Ellman's reagent to form a new mixed disulfide and a 2-nitro-5-thiobenzoate (TNB) byproduct. Upon addition of base, TNB is deprotonated to form a dianion, which absorbs light in the visible region and can be detected using UV-Vis spectroscopy. Ellman's Reagent CO₂H -NO₂ internal disulfide crosslink O₂N- HO₂C SH solvent- exposed thiol UV Absorbance at 412 nm O₂N- -S TNB²- alkaline pH O₂N- SH HO₂C 2-nitro-5-thiobenzoate (TNB) -NO2 mixed disulfide CO₂H a) Provide a detailed…
5 (a) Describe in detail how you will determine the primary structure of protein. (c) You have been given a mixture of lysine, histidine and cysteine. The isoelectric point of the amino acids are as follows: Histidine 7.64 Lysine 9.74 Cystenie 5.02 Show how you will separate the mixxture into the pure forms. State and describe any instrument that you will use to separate the components in the mixture.
A protein has a stability ranging from 6 to 15 kcal/mole at 37 OC. Stability is a measureof the equilibrium between the folded and unfolded protein given by the relationship; folded(F) = unfolded (U), k=[U]/[F] For a protein with a stability of 10 kcal/mole, calculate the fraction of unfolded proteinthat would exist at equilibrium at 37 OC. Use the following equation:GO=RTlnk=-2.3RTlog k,where R=1.98 x 10-3 kcal/mole and T is temperature in Kelvin (K) and k is theequilibrium constant.
macollege.instructure.com/courses/352/pages/covid-proteins-lab-manual?module_item_id=D44333 A = abc Where "A" is absorbance, "a" is molar absorptivity, "b" is the path length (length of the cuvette in units of cm), and "c" is concentration (mol/L). The molar absorptivity is an intrinsic property of a molecule which tells us how intensely it will absorb at a particular wavelength. If "A" is a unitless quantity, "b" is in units of cm, and "c" is in units of mol/L, then what are the units of molar absorptivity? Do a little research to learn how alpha-helices and beta-sheets are drawn in protein structures. If most of the absorption properties are coming from the alpha-helices in these proteins, and many alpha-helices have similar absorbance properties across different proteins, which protein would you predict would have the highest molar absorptivity? Your job is to use the following data table to determine the molar absorptivity for each of the following proteins at their respective…
8. The following proteins represent a wide range of molecular weights and isoelectric points. Mr is the molecular weight of a single protein chain. • Protein 1: Mr 68,544; pl 6.11 (monomer) • Protein 2: Mr 29,041; pl 5.32 (dimer) • Protein 3: Mr 15,805; pl 5.7 (dimer) • Protein 4: Mr 12,165; pl 4.74 a. Which protein is the most acidic? Explain your answer. b. Which protein will migrate the slowest in an SDS-PAGE? Explain your answer. c. In what order will these proteins elute from a cation exchanger at pH 8? Explain your answer. d. In what order will these proteins salt out from a pH 7 solution by the dropwise addition of saturated ammonium sulfate? Explain your answer. 5 83°F Cloudy
All amino acids have two ionizable functional groups: an a-amino group (average pK, of 9.4) and an a-carboxylic acid group (average pK, of 2.2). Lysine also has an ionizable side chain (R group) with a pK, of about 10.5. One of the possible ionization states of lysine is shown in the image. i H₂N-CH-C-OH CH₂ 1 Incorrect CH₂ CH₂ CH₂ NH₂ At what pH would the structure be the predominant ionization state? Consider the ionization state of all three of the functional groups. Show Transcribed Text 11.9 S The protonated form of the R group of lysine is shown in the structure. The ratio of the charged (protonated) form to the deprotonated form depends on the pK, of the R group and the pH of the solution. 12.0 10.5 5.4 Select all the pH values at which the charged form of the R group would predominate. 2.2
Q: 1.5%. Sucrose by massx M what volume f soft,dmink Solin Noitolu millimeter contain' 5:29 of Suvrose bolovitine 102 102 24A) nioino) 220 ud s d ro tnaroa 220M 220m V
Given the information below: Amino Acid Source Bioactivity pH Aspartic Acid (Asp) / D Bone Enzyme 4 pK1 = 2.09 pK2 = 9.82 рКЗ 33.86 CH2 C=O Answer the following: A. Amino acids and proteins are the major buffer constituents of the blood and some body fluids. The amino acid is Aspartlc Acld. What will be the weak acid and conjugate base forms of the buffer prepared from the amino acid? (Use the pKa values given). B. If you are to make 0.1 M of the buffer, what should be the molar concentration of the weak acid form and the conjugate base of the amino acid?
Bilayer leaflet CO COON 1. Unfolded peptide aqueous phase 2. Unfolded peptide in membrane 3. α-helix in membrane Figure 1: Membrane binding peptide of a glycosyltransferase is shown interacting with a membrane. Positive charges are shown as blue +, negative charges are shown as red -. 7. (3%) While the membrane binding peptide is in solution it is shown as being "un- folded" in Figure 1. (a) What is the name we give to this type of secondary structure? (Answer with 1 sentence) (b) What is a general role of this type of secondary structure in a protein? Answer with proy
The triprotic form of the amino acid cysteine is shown below, along with the pK, value for each ionizable site. The isoelectric point (pl) for cysteine occurs at pH= 5.1. B 10.8 CH₂ SH C13 A LA -OH (1) What is the charge on the molecule at the isoelectric point? (2) In the predominant form of the molecule at the isoelectric point, is each of the sites (labeled A, B, and C) protonated or unprotonated? site A site B: site C