Ramačandranov dijagram

Ramačandranov dijagram (Ramačandranov grafikon, [φ,ψ] grafikon), koji su originalno (1963) razvili G. N. Ramačandran, C. Ramakrišnan, and V. Sasisekharan,^[1] je način vizuelizacije diedralnih uglova ψ naspram φ aminokiselinskih ostataka proteinske strukture. Slika levo ilustruje definiciju φ i ψ diedralnih uglova osnove lanca^[2] (φ i φ' po Ramačandranu). Ugao ω peptidne veze je normano 180°, pošto parcijalni karakter dvostruke veze drži peptid u ravni.^[3] Slika gore desno prikazuje dozvoljene φ,ψ konformacione regione osnove lanca po Ramačandranu et al. iz 1963. i 1968, koristeći proračune trvdih sfera: pun radijus je prikazan punim linijama, redukovani radijus isprekidanim, i relaksirani tau (N-C_alfa-C) ugao tačkastim linijama.^[4] Pošto su vrednosti diedralnih uglova cirkularne i 0° je isto što i 360°, ivice Ramačandranovog dijagrama se „obmotavaju“, leva strana sa desnom, i dno sa vrhom. Na primer, mala traka dozvoljenih vrednosti duž donjeg levog ugla grafikona je nastavak velikog regiona gore levo.

Reference

^ Ramachandran, G.N.; Ramakrishnan, C.; Sasisekharan, V. (1963). „Stereochemistry of polypeptide chain configurations”. Journal of Molecular Biology. 7: 95—9. PMID 13990617. doi:10.1016/S0022-2836(63)80023-6.
^ Richardson, J.S. (1981). „Anatomy and Taxonomy of Protein Structures”. Advances in Protein Chemistry. 34: 167—339. PMID 7020376. doi:10.1016/S0065-3233(08)60520-3.
^ Pauling, L.; Corey, H.R.; Branson (1951). „The Structure of Proteins: Two Hydrogen-Bonded Helical Configurations of the Polypeptide Chain”. Proceedings National Academy of Sciences USA. 37 (4): 205—211. PMC 1063337  . PMID 14816373. doi:10.1073/pnas.37.4.205.
^ Ramachandran, G.N.; Sasiskharan, V. (1968). „Conformation of polypeptides and proteins”. Advances in Protein Chemistry. 23: 283—437.

Literatura

Richardson, J.S. (1981). „Anatomy and Taxonomy of Protein Structures”. Advances in Protein Chemistry. 34: 167—339. PMID 7020376. doi:10.1016/S0065-3233(08)60520-3. , available on-line at Anatax^{[мртва веза]}
Branden, C.-I.; Tooze, J. (1991), Introduction to Protein Structure, Garland Publishing, NY, ISBN 0-8153-0344-0

Spoljašnje veze

[1] Ramachandran, G.N.; Ramakrishnan, C.; Sasisekharan, V. (1963). „Stereochemistry of polypeptide chain configurations”. Journal of Molecular Biology. 7: 95—9. PMID 13990617. doi:10.1016/S0022-2836(63)80023-6.

[2] Richardson, J.S. (1981). „Anatomy and Taxonomy of Protein Structures”. Advances in Protein Chemistry. 34: 167—339. PMID 7020376. doi:10.1016/S0065-3233(08)60520-3.

[3] Pauling, L.; Corey, H.R.; Branson (1951). „The Structure of Proteins: Two Hydrogen-Bonded Helical Configurations of the Polypeptide Chain”. Proceedings National Academy of Sciences USA. 37 (4): 205—211. PMC 1063337  . PMID 14816373. doi:10.1073/pnas.37.4.205.

[4] Ramachandran, G.N.; Sasiskharan, V. (1968). „Conformation of polypeptides and proteins”. Advances in Protein Chemistry. 23: 283—437.

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