1. In 1943, Frederick Sanger received his doctoratefor his research project which studied the metabolism of lysine in animal body.Further in 1943, he joined Albert C. Chibnall and his research group at thebiochemistry department in Cambridge and started working on sequencing of aminoacids of insulin.
This research was successful, and Sanger thus determined theamino acid sequence of chains A and B of bovine insulin in 1951 and 1953respectively. He was awarded The Nobel Prize in 1958 for his work on thedetermination of structure of insulin molecule. 2. AQSOWCDEUVFRGBTNHYMKIZLP Ala-Gln-Ser-Pyl-Trp-Cys-Asp-Glu-Sec-Val-Phe-Arg-Gly-Asx-Thr-Asn-His-Tyr-Met-Lys-Ile-Glx-Leu-Pro 3. Edmond H. Fisher and Edwin G.
Krebs won the Nobel Prize inPhysiology or Medicine in 1992 for their discovery in reversible proteinphosphorylation and its importance as biological mechanism. The research:-Fisher and Krebsstarted studying the regulation of glycogen phosphorylase. Step 1 – Purifiedphosphorylase to get pure enzyme.Step 2 – Grindingof rabbit muscle, extracting in water and squeezing it in cheesecloth.Step 3 –clarifying the turbid extract by passing it through a battery of filter papers. Observations: -extracted muscle contained inactive phosphorylase, which when passed through afilter paper, became activated. This is due to the contamination of filterpaper with calcium ions. Also, they proved that the filtered crude musclecontained ATP by labelling it with ?-ATP32, which proved that radioactivity hadbeen incorporated in the isolated protein and was just phosphorylated.
Conclusion: -Activation of phosphorylase required presence of Ca+, Mg +, ATP and kinaseenzyme. Mechanism:-They thus found the molecular mechanisms whichleads to the interconversion of the two forms of phosphorylase and hence termedthe process as reverse phosphorylation. Their research proved so by elucidatingvarious processes the phosphatases and kinases undergo that lead to thereversal. They showed the following:· The enzyme phosphorylase converts glycogen to glucose whichserves as a fuel for muscle contraction. This enzyme is activated by additionof phosphate group carried out by protein kinase.· Phosphorylase can be inactivated by the removal of thephosphate group which is carried out by the enzyme phosphatase, thus reversingthe phosphorylation process.· The regulation of phosphorylation and reverse phosphorylationis well maintained balance between the phosphatases and kinases.
4. Leu-Sec-Lys-His-Gly-Phe_Xaa-Asp-Ser-Ala-Gln-Trp-Glu-Arg-Glx-Thr-Tyr-Ile-Pro-Orn-Met-Asn-Val-Cys LUKHGFXDSAQWERZTYIPXMNVC 5. a. SDEKAINVKWQLA– neutral at physiological pH, charge = 0b. SDEKAINVKWQHA– neutral at physiological pH, charge = 0c. SEERAINVAWQHA– negatively charged at physiologicalpH, charge = -1d. SDEKAINVKWQEA– negatively charged at physiological pH, charge = -1e. EEERAINVKWQKA- neutral at physiological pH, charge = 0 Calculated the above charges based onfollowing:- Amino Acid Charge at physiological pH Glutamic acid (E) -1 Aspartic acid (D) -1 Lysine (K) +1 Arginine (R) +1 Histidine (H) 0 (because pka is smaller than ph, hence it would be deprotonated) 6.
The following results were obtained when sequence alignmentof ?-hemoglobin and ?-hemoglobin was carried out using BLAST- Identity in blast is the extent to which twoprotein sequences are have the exact same residues at the same position in asequence alignment performed. Hence, it can be concluded from the above resultsthat these two sequences are similar. They have 43% similarity.The bioinformatics tool, BLAST is very userfriendly and easy to use. Hence I did not run into any trouble while using it. 7.
Multiple ionizable functionalgroups of Histidine at various pHs and charges. 8. Ala (A) Arg (R) Asn (N) Asp (D) Cys (C) Gln (Q) Glu (E) Gly (G) His (H) Ile (I) Leu (L) Lys (K) Met(M) Phe (F) Pro (P) Ser (S) Thr (T) Trp (W) Tyr (Y) Val (V) Pyl (O) Sec (U) (B) (Z) (X) 14.8% 2.1% 2.8% 5.
6% 0.7% 0.7% 2.8% 4.
9% 7.0% 0.0% 12.7% 7.7% 2.1% 4.
9% 4.9% 7.7% 6.3% 0.7% 2.1% 9.2% 0.
0% 0.0% 0.0% 0.0% 0.
0% Ala (A) Arg (R) Asn (N) Asp (D) Cys (C) Gln (Q) Glu (E) Gly (G) His (H) Ile (I) Leu (L) Lys (K) Met(M) Phe (F) Pro (P) Ser (S) Thr (T) Trp (W) Tyr (Y) Val (V) Pyl (O) Sec (U) (B) (Z) (X) 10.2% 2.0% 4.1% 4.8% 1.
4% 2.0% 5.4% 8.8% 6.
1% 0.0% 12.2% 7.5% 1.4% 5.4% 4.8% 3.4% 4.
8% 1.4% 2.0% 12.2% 0.0% 0.
0% 0.0% 0.0% 0.0% Amino acid composition of ?-hemoglobin Aminoacid composition of ?-hemoglobin Ala (A) Arg (R) Asn (N) Asp (D) Cys (C) Gln (Q) Glu (E) Gly (G) His (H) Ile (I) Leu (L) Lys (K) Met(M) Phe (F) Pro (P) Ser (S) Thr (T) Trp (W) Tyr (Y) Val (V) Pyl (O) Sec (U) (B) (Z) (X) 8.26% 5.53% 4.
05% 5.46% 1.37% 3.93% 6.73% 7.08% 2.27% 5.
93% 9.65% 5.82% 2.41% 3.86% 4.72% 6.61% 5.
35% 1.09% 2.92% 6.86% 0.0% 0.0% 0.0% 0.0% 0.
0% Average amino acidcomposition of all UniProt/SwissProt Entries It can thus be noted from above the tables that the aminoacid compositions of ?-hemoglobin and ?-hemoglobin are similar to each other. Comparing it with the Uniprot/SwissBank entries, thefindings are- · Neither the ? or ?chain contain any Isoleucine. · There is an abundanceof the non-polar aliphatic R group amino acids like glycine, lysine, leucineetc. This can be explained by the hydrophobicity and non-polar nature,increasing their folding in many forms.
Tools used:-· BLAST References:-· https://www.ncbi.nlm.nih.gov/books/NBK62051/· https://www.ibiology.org/cell-biology/reversible-protein-phosphorylation-regulatory-mechanism/· https://www.britannica.com/biography/Edmond-H-Fischer#ref267469· https://www.ncbi.nlm.nih.gov/· https://www.nobelprize.org/nobel_prizes/medicine/laureates/1992/press.html· https://en.wikipedia.org/wiki/Frederick_Sanger