How do you calculate hydrophobicity of a protein?
Estimation of protein hydrophobicity based on the amino acid composition. It has already been shown that the hydrophobicity of a protein can be estimated by assessing the contribution of every amino acid located on its surface based on its exposed surface and a suitable hydrophobicity scale.
How do you calculate aliphatic index?
The aliphatic index of a protein is calculated according to the following formula : Aliphatic index = X(Ala) + a * X(Val) + b * ( X(Ile) + X(Leu) ) where X(Ala), X(Val), X(Ile), and X(Leu) are mole percent (100 X mole fraction) of alanine, valine, isoleucine, and leucine.
How do you calculate protein MW?
How to calculate protein molecular weight from the sequence? It’s just as simple as it seems – add together all the molecular weights of the amino acids present in your sequence. You also need to subtract the molecular weight of water for every bond created.
How do you calculate the isoelectric point of a peptide?
Calculating approximate isoelectric points for amino acids and peptides: Amino acids: If the side chain does not have an ionizable group, then the pI is simply the average of the α- NH3 and α-COOH pKa values. If the side chain has an ionizable group then all three pKa values must be considered.
How is hydrophobicity measured?
Hydrophobicity is measured in terms of the contact angle of the water drops to the surface of textiles (Fig. 10.7). A contact angle greater than 90 degrees is said to be hydrophobic and more than 150 degrees superhydrophobic.
What is a good aliphatic index?
The relative volume of a protein occupied by its aliphatic side chains is termed as Aliphatic index (AI). The aliphatic index of cytotoxins in the range of 66.5 to 84.33 indicated that these proteins are thermally stable as well as they contain high amount of hydrophobic amino acids.
What is an aliphatic index?
Abstract. A statistical analysis shows that the aliphatic index, which is defined as the relative volume of a protein occupied by aliphatic side chains (alanine, valine, isoleucine, and leucine), of proteins of thermophilic bacteria is significantly higher than that of ordinary proteins.
What is the molecular weight range of proteins?
The broad range protein molecular standards include 11 proteins from 6500 to 205,000 daltons for use as molecular weight standards in SDS-polyacrylamide gel electrophoresis.