2.1.8.2. Absorbency Under Load (AUL) - BADA

2- Side chains of polar residues with positive or negative charges, such as Arginine, Lysine,
Aspartic acid and Glutamic acid are usually on the surface of the protein in contact with the
aqueous solvent.
3- Uncharged polar side chains, such as Serine, Threonine, Aspargine, Glutamine, Tyrosine and
Tryptophan are frequently located on the surface, but some of this are found in the interior as
well as they are found in the interior, they are practically hydrogen bonded to other similar
residues. In fact, hydrogen bonding helps neutralize the polarity of these groups [18] .
Table 1. 22 Polar and non-polar amino acids found in proteins [18]
Structure of R Amino Acid Abbreviations
─H
─CH3
─CH(CH3) 2
─CH2CH (CH3) 2
─CH2CH (CH3) 2
│
CH3
─CH2CO NH 2
─CH2CH2CO NH 2 Glutamine Gln
…………………………………………………..7
Side chain
polarity
Side chain
charge (pH 7)
Glycine Gly nonpolar neutral
Alanine Ala nonpolar neutral
Valine Val nonpolar neutral
Leucine Leu nonpolar neutral
Isoleucine Ile nonpolar neutral
Phenylalanine Phe nonpolar neutral
Asparagine Asn polar neutral
polar negative