Α-helix
From WikiMD's Wellness Encyclopedia
Template:Infobox protein structure An α-helix (alpha helix) is a common secondary structure of proteins and is a right-handed coiled or spiral conformation. It is a major structural motif in proteins and is characterized by a specific pattern of hydrogen bonding between the backbone amide and carbonyl groups of the peptide bond.
Structure[edit | edit source]
The α-helix is stabilized by hydrogen bonds between the N-H group of one amino acid and the C=O group of another amino acid four residues earlier. This results in a helical structure with 3.6 amino acids per turn and a pitch of 5.4 Å. The side chains of the amino acids in an α-helix extend outward from the helical backbone.
Discovery[edit | edit source]
The α-helix was first proposed by Linus Pauling, Robert Corey, and Herman Branson in 1951 as part of their work on the structure of proteins. Their model was based on X-ray crystallography data and chemical principles.
Function[edit | edit source]
α-helices are a fundamental component of the tertiary structure of proteins and play a crucial role in the function of many proteins. They can form coiled-coil structures, transmembrane helices, and are involved in the binding of ligands and substrates.
Examples[edit | edit source]
Many proteins contain α-helices, including hemoglobin, myoglobin, and keratin. The α-helix is also a key structural element in DNA-binding proteins and membrane proteins.
Related Structures[edit | edit source]
Other common secondary structures in proteins include the β-sheet and the β-turn. These structures, along with the α-helix, contribute to the overall folding and stability of proteins.
See Also[edit | edit source]
- Protein structure
- Secondary structure
- Tertiary structure
- Quaternary structure
- Hydrogen bond
- Peptide bond
- Linus Pauling
- X-ray crystallography
References[edit | edit source]
Navigation: Wellness - Encyclopedia - Health topics - Disease Index - Drugs - World Directory - Gray's Anatomy - Keto diet - Recipes
Search WikiMD
Ad.Tired of being Overweight? Try W8MD's physician weight loss program.
Semaglutide (Ozempic / Wegovy and Tirzepatide (Mounjaro / Zepbound) available.
Advertise on WikiMD
WikiMD is not a substitute for professional medical advice. See full disclaimer.
Credits:Most images are courtesy of Wikimedia commons, and templates Wikipedia, licensed under CC BY SA or similar.