Describe why Histidine is often found in active sites and is involved in the catalytic mechanisms...

Describe why Histidine is often found in active sites and is involved in the catalytic mechanisms of enzymes. What role does it generally play in catalytic mechanisms? Draw an example of a catalytic mechanism that involves Histidine as a critical amino acid residue.

Expert Solution

Histidine has an imidazole ring which can be protonated and deprotonated depending on the physiological pH. So, it can perform different roles in catalysis. Its pKa is 6 so it can be protonated and deprotonated very easily at physiological pH. When protonated it acts as a proton donor (acid) and when it is deprotonated it acts as a proton acceptor (base). Histidine also acts as electron donor (lewis base) to act as ligand for a metal ion for the metalloenzymes.

Reaction involving histidine: Protons are transferred from serine to histidine. Here histidine acts as a base.

gladiator answered 2 years ago

Histidine often shows up as a key player in enzymatic reaction mechanisms and likewise often serves...

Histidine often shows up as a key player in enzymatic reaction mechanisms and likewise often serves as one of the catalytic residues in the active site of many different types of enzymes. Suggest several reasons why histidine has this versatility. What sorts of useful chemical properties does Histidine possess that enable it to facilitate enzymatic reactions?

Describe the active (binding) sites of Hb, Hc and Hr.

Describe the possible mechanisms involved in the development of atherosclerosis. Describe mechanisms of development of atheroschlerosis....

Describe the possible mechanisms involved in the development of atherosclerosis. Describe mechanisms of development of atheroschlerosis. Discuss the major risk factors for atherosclerosis. Describe the major complications of atherosclerosis. Discus the arterial involvement in atherosclerosis. List the clinical manifestations of atherosclerosis.

Describe two specific catalytic mechanisms that enzymes may use to speed up a reaction and describe...

Describe two specific catalytic mechanisms that enzymes may use to speed up a reaction and describe two molecular mechanisms which regulate enzyme activity

Describe a several types of defensive mechanisms ( both passive types and active types) that prey...

Describe a several types of defensive mechanisms ( both passive types and active types) that prey use to avoid capture and/ or defend themselves from predators.

In your own words, describe three mechanisms of transcriptional regulation, that are involved in controlling the...

In your own words, describe three mechanisms of transcriptional regulation, that are involved in controlling the rate of expression of hydrolytic enzymes associated with lysosomes. For each mechanism described, include whether the rate of expression would be increased or decreased.

Explain the different forms of membrane transport: Passive, Facilitated, Active. Describe the bulk transport mechanisms of...

Explain the different forms of membrane transport: Passive, Facilitated, Active. Describe the bulk transport mechanisms of Endocytosis and Exocytosis.

8. Describe an electrospray ionization source and the mechanisms involved for the generation of gas-phase ions....

8. Describe an electrospray ionization source and the mechanisms involved for the generation of gas-phase ions. How does this compare to a DESI source for mass spectrometry?

Investment Bankers often become involved with the mergers and acquisitions of firms. So, why might a...

Investment Bankers often become involved with the mergers and acquisitions of firms. So, why might a firm need an investment banking firm to both initiate and complete either the merger or acquisition of a firm...and, tell us what the difference is between a merger and an acquisition. In addition, as CEO (chief investment officer) of the firm, you are to determine the best time to commence the merger/acquisition and the terms of the purchase/take-over. What type of questions might you...

1.Describe the various mechanisms involved in the regulation gene transcription. •RNAi •Epigenetics •Regulatory elements can u...

1.Describe the various mechanisms involved in the regulation gene transcription. •RNAi •Epigenetics •Regulatory elements can u tell me plzz in brief

Question