Search results
Results from the WOW.Com Content Network
The pH-dependence of the activity displayed by enzymes and the pH-dependence of protein stability, for example, are properties that are determined by the pK a values of amino acid side chains. The pK a values of an amino acid side chain in solution is typically inferred from the pK a values of model compounds (compounds that are similar to the ...
Also, amino acid side chain affinity for water was measured using vapor phases. [14] Vapor phases represent the simplest non polar phases, because it has no interaction with the solute. [18] The hydration potential and its correlation to the appearance of amino acids on the surface of proteins was studied by Wolfenden.
For amino acids with uncharged side-chains the zwitterion predominates at pH values between the two pK a values, but coexists in equilibrium with small amounts of net negative and net positive ions. At the midpoint between the two p K a values, the trace amount of net negative and trace of net positive ions balance, so that average net charge ...
Amino acid Short Abbrev. Side chain Hydro-phobic pKa § Polar pH Small Tiny Aromatic or Aliphatic van der Waals volume (Å 3) Alanine: A Ala -CH 3 - - Aliphatic 67 Cysteine: C Cys -CH 2 SH: 8.55 acidic - 86 Aspartic acid: D Asp -CH 2 COOH 3.67 acidic - 91 Glutamic acid: E Glu -CH 2 CH 2 COOH 4.25 acidic - 109 Phenylalanine: F Phe -CH 2 C 6 H 5 ...
Serine (symbol Ser or S) [3] [4] is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated − NH +3 form under biological conditions), a carboxyl group (which is in the deprotonated − COO −
The N-O distance required is less than 4 Å (400 pm). Amino acids greater than this distance apart do not qualify as forming a salt bridge. [11] Due to the numerous ionizable side chains of amino acids found throughout a protein, the pH at which a protein is placed is crucial to its stability.
Asparagine (symbol Asn or N [2]) is an α-amino acid that is used in the biosynthesis of proteins.It contains an α-amino group (which is in the protonated −NH + 3 form under biological conditions), an α-carboxylic acid group (which is in the deprotonated −COO − form under biological conditions), and a side chain carboxamide, classifying it as a polar (at physiological pH), aliphatic ...
Many applications exist in biochemistry; for example, the pK a values of proteins and amino acid side chains are of major importance for the activity of enzymes and the stability of proteins. [67] Protein pK a values cannot always be measured directly, but may be calculated using theoretical methods.