PROPROTEIN Meaning and
Definition
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A proprotein is a type of protein molecule that undergoes post-translational modifications to become an active protein. It is derived from the translation of a specific gene, which results in the synthesis of an inactive or partially active protein called a proprotein. This proprotein typically requires additional processing steps, such as cleavage or modification, to become fully functional and exert its biological activity.
Proproteins are often larger in size and contain amino acid sequences that can be enzymatically modified. These modifications can include the removal of specific amino acids or the addition of functional groups. The activation of proproteins usually occurs within the cellular compartments where they are synthesized, although it can also take place in other locations within the organism.
The processing and activation of proproteins are crucial for their correct function and regulation. This activation can be tightly controlled by factors such as enzymes, specific conditions within the cellular environment, or specific signals received from other cells or molecules.
Examples of proproteins include hormone precursor molecules, such as proinsulin, which undergoes proteolytic cleavage to release insulin, and prohormone convertases, which process various hormones in the endocrine system. Additionally, certain growth factors, peptide neurotransmitters, and enzymes can also exist as proproteins.
In summary, a proprotein is an inactive or partially active protein that requires post-translational modifications to become fully functional. These modifications involve specific enzymatic processes that regulate the activation and release of the active protein.
Etymology of PROPROTEIN
The word "proprotein" is a blend of the prefix "pro-" and the word "protein".
The prefix "pro-" in this context comes from the Greek word "pro", meaning before or in front of. It is commonly used in scientific terms to indicate a precursor or an earlier stage of something.
The word "protein" comes from the French word "protéine", coined in the mid-19th century by the Dutch chemist Gerardus Johannes Mulder. Mulder derived it from the Greek word "proteios", meaning primary or of prime importance, as proteins were considered essential components of living organisms.
So, when combined, "proprotein" refers to a precursor form or an inactive form of a protein that can be further processed and activated into the mature and functional protein.
