Valine

Abbrev. V Val
Full Name Valine
Side chain type
hydrophilic
Mass
117.15
pl
6.00
pK1(α-COOH)
2.39
pK2(α-+NH3)
9.74

Side chain CH(CH3)2
Hydro- phobic
yes
Polar
no
Charged
no
Small
yes
Tiny
no
Aromatic or Aliphatic
Aliphatic
van der Waals volume
105
Codon
GUU, GUC, GUA, GUG
Occurrence in proteins (%)
6.6

Remarks: Essential for humans. Behaves similarly to isoleucine and leucine. See isoleucine.

Valine is one of the 20 natural amino acids, and is coded for in DNA. Nutritionally, valine is also an essential amino acid. It is named after the plant valerian.

In sickle-cell disease, it substitutes for the hydrophilic amino acid glutamic acid in hemoglobin: Because valine is hydrophobic, the hemoglobin does not fold correctly. Valine is uncharged overall, as its R group is neutral, and the charges from its amino and carboxylic acid groups balance out: a zwitterion.

Foods that are good sources of valine include cottage cheese, fish, poultry, beef, peanuts, sesame seeds, and lentils.

In a 1994 report released by five top cigarette companies, valine is one of the 599 additives to cigarettes. Its use or purpose, however, is unknown, like most cigarette additives.

 

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