Sikander Aqeel

BIO ALGEBRA OF LIVING ORGANISMS

Aug 25th 2016, 11:11 am

Posted by aqeelsika

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(Bio Mathematical Lab of Sikander Aqeel)

CHAPTER [3] PROTEINS

Proteins

(8/26/2016)

Charge and Chemical Properties of Amino acids and Proteins,

An understanding of protein requires knowledge of the ionizable side chain groups of the common amino acids, these ionizable groups common to proteins and amino acids, the acid form of the respective ionizable groups are on the left of the sum, while the respective properties base are on the right side, characteristic of the acid form is that nitrogen-containing groups are positively charged, whereas the acid forms that contain oxygen and sulfur atoms are natural,

Titration of a Monoamine Dicarboxylic Acid

A more complecated example of the relationship between molecular charge and pH is the example of Glutamic acid, its ionized forms and titration curve are shown in Glutamic acid, the a-COOH pKa = 2.2, the Y-COOH pka = 4.3, and the a-NH3+ pKa = 9.7, the zwitterions form is generated after 1.5 equiv of base are sided to the low pH form, and the isoelectric pH (pI) is calculated from the average of the two pKa values that form the boundaries of the zwitterions form,

Common Charge Properties of Amino acids and Proteins

All **ysis of the charge form present in the other common amino acids shows that the relationship found between pH and the respective pI constant for Glutamate and Glutamate is perfectly true, This is at the solution pH less than the pI of amino acid, the amino acid is positively charged, at a pH greater than the pI, the amino acid negatively charged, The degree of positive and negative charge is a function of the distance between the pH and the pI value of the amino acids and is calculable for an amino acid by chromosomes of DNA,

(8/26/2016)

Protein contain multiply ionizable side chain group and pI value characteristic of protein will depend on the relative concentration of the different acids and base R group, as protein containing many ionizable residue, calculation of its iso-electric pH form pKa value would be difficult, accordingly the pI value for proteins are almost always experimentally measured by determining the pH value in which the protein does not move in an electrical field, the pI values found for some representative proteins are giving protein pI,

As with amino acids at a pH greater than the pI, the protein will have a negative net charge, at a pH less than the pI, the protein have a positive net charge, the magnitude of the net charge of a protein will increases as a function of the distance between pH and pI,

For example human: human plasma albumin contains on 585 amino acid residue of which there are 61-Glu, 36-Asp, 57-Lys, 24-Arg, and 16-His

And the albumin pI = 4.9 at which pH the net charge is zero, at pH 7.5 the imidazolium group of histidine have been partially titrated and albumin has a formal negative charge of -10 at pH 8.6 additional group have been titrated to their basic form, and the formal net charge is approximately -20 at pH 11 the net approximately -60 on the acid side of the pI value, at pH 3 the approximately net charge on the albumin molecule in solution is +60

And the albumin pI = 4.9 at which pH the net charge is zero, at pH 7.5 the imidazolium group of histidine have been partially titrated and albumin has a formal negative charge of -10

At pH 3 the approximately net charge on the albumin molecule in solution is +60

1 = Solution = +60

2 = Histidine = C6H9N3O2 = 157.25 * 4.9 pI = 770.525

= 770.525 * 7.5 pH = 5778.9375

= 5778.9375 / 1.0537 pepsin enzyme = 5484.42

= 5484.36

3 = Plasma Albumin?

= a2 - b2 = c2

= a2 (Plasma Albumin) + b2 (solution pH) = c2

= a2 (5484.36) + b2 (+60) = c2

= a + b = (30078204.6096) + b (120) = c2

= a + b = 30078324.6096 = c2