Tertiary structure
Overall 3-D shape of protein
Result from irregular contortions from bonding between side chains (R-groups) of various amino acids.
Hydrophobic interactions are a strong determinant in protein folding (a.a. with hydrophobic R-groups congregate at core of protein)
H-bonds, ionic interactions, and disulfide bridges of side chains also involved in stabilizing the tertiary structure.
Overall 3-D shape of protein
Result from irregular contortions from bonding between side chains (R-groups) of various amino acids.
Hydrophobic interactions are a strong determinant in protein folding (a.a. with hydrophobic R-groups congregate at core of protein)
H-bonds, ionic interactions, and disulfide bridges of side chains also involved in stabilizing the tertiary structure.
Quaternary structure
Some proteins consist of two or more polypeptide chains.
Quaternary structure is the overall protein structure that results from the aggregation of these polypeptide units
e.g. collagen = triple helix (3 subunits)
e.g hemoglobin = 2 alpha and 2 beta subunits
In addition to primary structure, protein conformation is also dependent on protein's environment (e.g. changes in temp, pH, of salt concentration can lead to protein denaturation ( unfolding of protein with resultant loss of function) (Fig 5.23)
We still can not fully predict the 3-D conformation by knowledge of primary sequence only. Too complex.
Some proteins consist of two or more polypeptide chains.
Quaternary structure is the overall protein structure that results from the aggregation of these polypeptide units
e.g. collagen = triple helix (3 subunits)
e.g hemoglobin = 2 alpha and 2 beta subunits
In addition to primary structure, protein conformation is also dependent on protein's environment (e.g. changes in temp, pH, of salt concentration can lead to protein denaturation ( unfolding of protein with resultant loss of function) (Fig 5.23)
We still can not fully predict the 3-D conformation by knowledge of primary sequence only. Too complex.
No comments:
Post a Comment