Why is proline frequently encountered at the places in the myoglobin and hemoglobin molecules where the polypeptide chain turns a corner?

What type of protein structure does the active form of Catechol-oxidase most likely possess?

Imagine that a mutation has been discovered in the HBA1 gene, where amino acid residue # 1 in the alpha subunit is changed from valine to lysine. The structure of these two amino acids is shown below. How would this mutation affect the mobility of HbA in the gel?a) HbA with this mutation would have the same mobility as normal HbAb) HbA with this mutation would have the same mobility as HbSc) HbA with this mutation would have a faster mobility than normal HbA O d) HbA with this mutation would have a mobility somewhere in between HbS and normal HbA

A schematic diagram of the helical structure of cytochrome b562 is reproduced below. Thisprotein belongs to the family of -proteins that have a four-helix bundle. Number the helices 1 – 4according to their N  C direction. Indicate relative orientations of the macrodipoles of helices 1 – 4adjacent to the diagram of cytochrome b562. Remember that according to the definition of a dipolethat the arrow points towards the positive end.

Determine the sequence of the following 10-mer of ferritin using the data below. i. Complete acid hydrolysis of the 10-mer results in identification of 1A, 1D, 1E, 1F, 1H, 1K, 2L, 1T, 1Y ii. Digestion of the 10-mer with chymotrypsin results in 3 fragments containing (D, H, K, T), (F, L) and (A, E, L, Y) iii. Digestion of the 10-mer with V8 protease, which cuts on the C-side of acidic amino acids, results in three fragments containing (D, F, L, Y), (A, E, L) and (H, K, T) iv. Digestion with trypsin results in a fragment H-T and a fragment with all the other amino acids v. Treatment of the 10-mer with FDNB followed by complete acid hydrolysis results in the following two derivatives, DNP-1 and DNP-2 vi. Treatment of the 10-mer with a carboxypeptidase results in a free threonine

The peptide aspartyl-glutamyl-leucyl-threonyl-alanine, shown in the sketch drawing window, has several ionizable groups. Adjust the charges to show the molecule as it would exist at pH 5.00. Use the pk values in the table below. pK, Values for Ionizable Groups of Amino Acids. Amino Acid pA, of a-COOH pA, of e-NH, pA, of Side Chain Isoelectric Point (pI) Alanine 235 9.87 6.11 Arginine 2.01 9.04 12.48 10.76 Asparagine 2.02 8.80 5.41 Aspartic acid 210 9.82 3.86 298 Cysteine 2.05 10.25 8.00 5.02 Glutzmic acid 2.10 9.47 4.07 3.08 Glutamine 217 9.13 5.65 Glycine 235 9.78 6.06 Histidine 7.11 9.18 6.10 7.64 Isoleucine 232 9.76 6.04 Leucine 233 9.74 6.04 Lysine 218 8.95 10.53 9.74 Methionine 2 28 9.21 5.74 Phenylalanine 2 58 9.24 5.91 Proline 2.00 10.60 6.30 Serine 221 9.15 5.68 Threonine 2.09 9.10 5.60 Trуptophan 238 9.39 5.88 Tyrosine 2 20 9.11 10.07 5.63 Valine 2 29 9.72 6.00 • Use the wedge hash bond tools to indicate stereochemistry where it exists. • If a group is 2chiral, do not use…

Write the anticodons for the following amino acids: a) Met   b) Trp    c)  Ser    d)   Leu

Based on your knowledge of the natural amino acids, what would you expect pKa of the sidechain of beta-(aminomethyl)succinic acid to be? Draw an appropriate titration curve for beta-(aminomethyl)succinic acid, labeling the axes, indicating the equivalence points and the pKavalues, and use a drawing to show the protonated/deprotonated forms.