Adenine phosphoribosyltransferase (aprt)

Definition

Adenine phosphoribosyltransferase (APRT) is an enzyme that catalyzes the conversion of adenine and 5-phosphoribosyl-1-pyrophosphate (PRPP) into adenosine monophosphate (AMP) and pyrophosphate. This reaction is an essential part of the purine salvage pathway, allowing cells to recycle adenine from degraded nucleotides and efficiently synthesize AMP, which is crucial for various cellular processes.

5 Must Know Facts For Your Next Test

1. APRT plays a vital role in the purine salvage pathway, enabling the recycling of adenine to support nucleotide synthesis.
2. Deficiencies in APRT can lead to an accumulation of adenine in the body, which is associated with certain medical conditions like kidney stones.
3. The enzyme operates by transferring a ribose phosphate group from PRPP to adenine, forming AMP while releasing pyrophosphate as a byproduct.
4. APRT is predominantly found in tissues with high rates of nucleotide turnover, such as the liver and brain.
5. The activity of APRT can be influenced by various factors including substrate availability and regulatory molecules within the cell.

Review Questions

• How does APRT function within the purine salvage pathway and what is its significance?
  • APRT functions by catalyzing the reaction between adenine and PRPP to form AMP and pyrophosphate. This reaction is significant because it allows cells to efficiently recycle adenine derived from nucleotide breakdown, conserving energy and resources needed for nucleotide synthesis. By facilitating this process, APRT ensures that cells can maintain adequate levels of AMP, which is critical for various cellular functions including energy transfer.
• Discuss the potential consequences of APRT deficiency on human health.
  • APRT deficiency can lead to an increased level of adenine in the body, resulting in various health issues. One major consequence is the formation of kidney stones due to adenine accumulation, which can crystallize and obstruct renal function. Additionally, this deficiency can disrupt normal purine metabolism and may contribute to metabolic imbalances or disorders associated with nucleotide homeostasis.
• Evaluate the role of APRT in metabolic disorders related to purine metabolism and its implications for treatment strategies.
  • APRT plays a crucial role in maintaining proper purine metabolism. In metabolic disorders like APRT deficiency, understanding the enzyme's function allows for potential therapeutic strategies aimed at managing excess adenine levels. For instance, targeted therapies could focus on enhancing the salvage pathways or utilizing dietary modifications to reduce adenine intake. Moreover, genetic counseling may be beneficial for families affected by such disorders, providing insight into the implications of APRT deficiencies and potential interventions to improve health outcomes.

Related terms

Purine Salvage Pathway: A metabolic pathway that recycles purines by converting free purines and nucleotide breakdown products back into nucleotides, thus conserving energy and resources.

5-Phosphoribosyl-1-pyrophosphate (PRPP): A key intermediate in both purine and pyrimidine biosynthesis, PRPP acts as a ribose phosphate donor in nucleotide synthesis.

Adenosine Monophosphate (AMP): A nucleotide that plays important roles in cellular energy transfer and signaling, AMP can be converted into ATP, the primary energy currency of the cell.