Q.16.21 - An Introduction to General, Organic, and Biological Chemistry

Question

What type of interaction would you expect between the R groups of the following amino acids in a tertiary structure?

a. cysteine and cysteine

b. aspartate and lysine

c. serine and aspartate

d. leucine and leucine

Step-by-Step Solution

Answer

a. It is a disulphide interaction

b. It is an ionic interaction

c. It is a hydrogen bonding interaction 

d. It is a hydrophobic interaction  

Part (a) Step 1: Given Information

cysteine and cysteine 

Determining the type of interaction between the R groups of cysteine and cysteine in a tertiary structure.

Part (a) Step 2: Explanation

It contains R-SH - thiol bunch in it the parallel side chain, and partakes in enzymatic responses, as a nucleophile. It goes through oxidation to give the disulfide subsidiary cysteine, which serves a significant underlying job in numerous proteins. The disulphide spans $\left(-{\mathrm{CH}}_2-\mathrm{S}-\mathrm{S}-{\mathrm{CH}}_{2^{-}}\right)$ shaped by these deposits connect the parts inside a polypeptide chain. It likewise engaged with the development of the circles of the spine. Hence It is a disulphide interaction.

Part (b) Step 1: Given Information

aspartate and lysine 

Determining the type of interaction between the R groups of aspartate and lysine in a tertiary structure.

Part (b) Step 2: Explanation

Aspartate is an adversely charged, polar amino acid that contains a carboxylic acid group. Lysine is an emphatically charged, polar amino acid containing an amino group. Aspartate is habitually engaged with salt - spans, where they pair with a decidedly charged amino acid, for example, Lysine to make balancing out hydrogen bonds, significant for protein stability. Hence It is an ionic interaction.

Part (c) Step 1: Given Information

serine and aspartate

Determining the type of interaction between the R groups of serine and aspartate in a tertiary structure.

Part (c) Step 2: Explanation

Aspartate is an adversely charged, polar amino acid that contains a carboxylic acid group. Serine is a polar, neutral amino acid containing an amino group. The negative oxygen structures bond with positive hydrogen from amide gathering of Serine to make balancing out hydrogen bonds. Hence It is a hydrogen bonding interaction.

Part (d) Step 1: Given Information

leucine and leucine
Determining the type of interaction between the R groups of leucine and leucine in a tertiary structure.

Part (d) Step 2: Explanation

Leucine is a fundamental, non-polar aliphatic amino acid. It contains an aliphatic hydrophobic isopropyl (4 carbon) side chain. At the point when leucine connects with other leucine called isoleucine which is an isomer of leucine both contain methyl bunch, which is hydrophobic in nature and draws in one another.

Hence It is a hydrophobic interaction.