Quaternary structure: Difference between revisions
Jump to navigation
Jump to search
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
The quaternary structure of a [[Protein|protein]] is the fourth level of organisation. It refers to the arrangement of cross-linked proteins (several [[Polypeptide|polypeptide]] chains inter-linked). The structure is held together by [[Hydrogen bonds|hydrogen bonds]], [[Disulphide bond|disulphide bonds]], [[Ionic bond|ionic bonds]] and [[Hydrophobic interaction|hydrophobic interactions]] <ref>Biology 1 for OCR, Mary Jones, Cambridge University Press (2008)</ref>. | The quaternary structure of a [[Protein|protein]] is the fourth level of organisation. It refers to the arrangement of cross-linked proteins (several [[Polypeptide|polypeptide]] chains inter-linked). The structure is held together by [[Hydrogen bonds|hydrogen bonds]], [[Disulphide bond|disulphide bonds]], [[Ionic bond|ionic bonds]] and [[Hydrophobic interaction|hydrophobic interactions]] <ref>Biology 1 for OCR, Mary Jones, Cambridge University Press (2008)</ref>. | ||
The simplest form is when two polypeptide chains (2 subunits) form a dimer, a more complicated example is that of haemoglobin. Haemoglobin has 4 subunits which interact to form the quaternary structure. Small changes to this allow it to carry oxygen round the body to organs. | The simplest form is when two polypeptide chains (2 subunits) form a dimer, a more complicated example is that of haemoglobin. Haemoglobin has 4 subunits which interact to form the quaternary structure. Small changes to this allow it to carry oxygen round the body to organs.<ref>Berg JM, Tymoczko JL, Stryer L. (2002) Biochemistry. 5th edition, New York: W H Freeman. Online version used, available at http://www.ncbi.nlm.nih.gov/books/NBK22550/</ref> | ||
=== References === | === References === | ||
<references /><br> | <references /><br> | ||
Revision as of 16:59, 15 November 2012
The quaternary structure of a protein is the fourth level of organisation. It refers to the arrangement of cross-linked proteins (several polypeptide chains inter-linked). The structure is held together by hydrogen bonds, disulphide bonds, ionic bonds and hydrophobic interactions [1].
The simplest form is when two polypeptide chains (2 subunits) form a dimer, a more complicated example is that of haemoglobin. Haemoglobin has 4 subunits which interact to form the quaternary structure. Small changes to this allow it to carry oxygen round the body to organs.[2]
References
- ↑ Biology 1 for OCR, Mary Jones, Cambridge University Press (2008)
- ↑ Berg JM, Tymoczko JL, Stryer L. (2002) Biochemistry. 5th edition, New York: W H Freeman. Online version used, available at http://www.ncbi.nlm.nih.gov/books/NBK22550/