Question

The compound shown below is the antiparasitic drug miltefosine

(a) Is this compound a glycerophospholipid?

(b) How does miltefosine likely cross the parasite cell membrane?
(c) In what part(s) of the cell would the drug tend to accumulate? Explain.
(d) Miltefosine binds to a protein that also binds some sphingolipids and some glycerophospholipids. What feature common to all these compounds is recognized by the protein? The protein does not bind triacylglycerols.

Short answer

(a) Miltefosine is not a glycerophospholipid.

(b) Miltefosine crosses the parasite cell membrane through the passive transporter.

(c) The drug mostly accumulates in the hydrophobic tail buried in the bilayer, and its polar head group is exposed to the solvent.

(d) The protein recognizes the phosphocholine head group possessed by some sphingolipids and glycerophospholipids, but it binds all phospholipids or triacylglycerols and thereby does not recognize the hydrocarbon tail.

Step-by-step solution

Introduction

Miltefosine is ananti-parasitic medication.It is effective against a variety of parasite species and bacteria and fungi that cause disease. The extended residence period in the body is one of the drug's key characteristics.

In the solution (a), the miltefosine is not a glycerophospholipid

A glycerol backbone makes up a glycerophospholipid but no such glycerol backbone can be found in Miltefosine.Because it includes both phosphate and an alkyl group, it is called an alkylphosphocholine.

In the solution (b), Miltefosine likely to cross the membrane

Miltefosine comprises hydrophilic and hydrophobic components, making it impossible to diffuse through the parasite membrane. However, Miltefosine must enter through a passive transporterto pass through the membrane as the membrane does not possess a specific active transporter for Miltefosine.

In the solution (c), the drug tend to accumulate in the membrane of the cell

Miltefosine is an amphipathic molecule because it includes both hydrophilic and hydrophobic portions.The amphipathic molecules are most likely to collect in membranes in which the hydrophobic tail is buried in the bilayer, which is concealed. However, its polar head is exposed to the solvent.

In the solution (d), the protein does not bind to triacylglycerol

Miltefosine recognizes the phosphocholine head group, which is also present in several sphingolipids and glycerophospholipids. Thus, Miltefosine binds to a protein that binds some sphingolipids and some glycerophospholipids together.

However, Miltefosine does not bind all phospholipids or triacylglycerols. Thus, it does not recognize the hydrocarbon tail.

Conclusion

As a result, Miltefosine is therefore not a glycerophospholipid. Miltefosine is transported through the parasite cell membrane by a passive transporter. The hydrophobic tail is where the medication accumulates the greatest. Miltefosine binds to the protein and forms a complex with sphingolipids and glycerophospholipids.