ZOOHCC - 501: Molecular Biology (Theory)
Unit 4: Translation
Inhibitors of protein synthesis
Inhibitors of protein synthesis are molecules that interfere with the
process of translation, which is the process by which genetic information in
mRNA is used to synthesize a protein. Translation involves the coordinated
action of many different proteins and RNA molecules, and inhibitors of
protein synthesis can target various steps in this process.
There are several types of inhibitors of protein synthesis, including
antibiotics and chemical inhibitors. Antibiotics are natural or synthetic
compounds that are produced by microorganisms and are used to treat
bacterial infections. Many antibiotics target bacterial protein synthesis by
inhibiting specific steps in translation, such as the binding of
aminoacyl-tRNA to the ribosome or the formation of peptide bonds between
amino acids.
Chemical inhibitors are synthetic compounds that can be designed to
specifically target different components of the translation machinery. They
can be useful for studying the mechanisms of translation and for developing
new drugs to treat bacterial infections. However, they can also have toxic
effects on eukaryotic cells and can lead to unwanted side effects if used
improperly.
In general, inhibitors of protein synthesis can be very effective in
treating bacterial infections, but it is important to use them judiciously
to avoid the development of antibiotic resistance and other negative
consequences.
Explanation
Inhibitors of protein synthesis are molecules that interfere with the
process of translation, the synthesis of proteins from mRNA. These
inhibitors can be broadly classified into two categories:
Antibiotics: Antibiotics are natural or synthetic compounds that are
produced by microorganisms and are used to treat bacterial infections. Many
antibiotics target bacterial protein synthesis by inhibiting specific steps
in translation. Examples of antibiotics that inhibit protein synthesis
include:
Aminoglycosides: These antibiotics bind to the small subunit of the
ribosome and interfere with the accuracy of translation.
Tetracyclines: These antibiotics bind to the small subunit of the ribosome
and prevent the attachment of aminoacyl-tRNA to the ribosome.
Macrolides: These antibiotics bind to the large subunit of the ribosome and
inhibit the elongation phase of translation.
Chemical inhibitors: Chemical inhibitors are synthetic compounds that can
be designed to specifically target different components of the translation
machinery. Examples of chemical inhibitors of protein synthesis
include:
Cycloheximide: This chemical inhibitor binds to the large subunit of the
ribosome and blocks the translocation step of translation.
Puromycin: This chemical inhibitor mimics an aminoacyl-tRNA and is
incorporated into the growing polypeptide chain, causing premature
termination of translation.
Chloramphenicol: This chemical inhibitor binds to the large subunit of the
ribosome and inhibits the peptidyl transferase activity, preventing the
formation of peptide bonds.
In general, inhibitors of protein synthesis can be very useful in studying
the mechanisms of translation and in developing new drugs to treat bacterial
infections. However, they can also have toxic effects on eukaryotic cells
and can lead to unwanted side effects if used improperly.
Difference between prokaryotic and eukaryotic translation
Prokaryotic and eukaryotic cells differ in many ways, including the process
of translation, which is the synthesis of proteins from mRNA. Here are 10
differences between prokaryotic and eukaryotic translation:
Ribosome size: Prokaryotic ribosomes are smaller (70S) than eukaryotic
ribosomes (80S).
Initiation factors: Prokaryotes have fewer initiation factors than
eukaryotes.
Shine-Dalgarno sequence: Prokaryotic mRNA contains a Shine-Dalgarno
sequence that helps to initiate translation, whereas eukaryotic mRNA does
not.
mRNA splicing: Eukaryotic mRNA may undergo splicing before translation,
removing introns and joining exons. Prokaryotic mRNA does not undergo
splicing.
Polycistronic mRNA: Prokaryotic mRNA can be polycistronic, meaning it
codes for multiple proteins. Eukaryotic mRNA is typically monocistronic,
coding for a single protein.
Post-translational modifications: Eukaryotic proteins may undergo
post-translational modifications, such as glycosylation or
phosphorylation, that are not found in prokaryotes.
Translation location: In prokaryotes, transcription and translation can
occur simultaneously, whereas in eukaryotes, transcription occurs in the
nucleus and translation occurs in the cytoplasm.
Elongation factors: Prokaryotes and eukaryotes use different elongation
factors in the process of translation.
Antibiotics: Some antibiotics target prokaryotic ribosomes and can be
used to treat bacterial infections. Eukaryotic ribosomes are not affected
by these antibiotics.
Translation regulation: Eukaryotic translation is more tightly regulated
than prokaryotic translation, with multiple mechanisms for controlling the
rate of protein synthesis.