peptide metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving peptides, compounds of two or more amino acids where the alpha carboxyl group of one is bound to the alpha amino group of another. [GOC:go_curators]

The peptide metabolic process encompasses a complex series of biochemical reactions involved in the synthesis, modification, degradation, and transport of peptides. These processes are essential for a multitude of cellular functions, including protein synthesis, signal transduction, and immune response. Here is a detailed breakdown of the key steps involved:

1. **Peptide Synthesis:** Peptides are assembled from amino acids through the process of translation, where mRNA sequences are decoded to create polypeptide chains.

2. **Post-Translational Modifications:** Once synthesized, peptides undergo various modifications, including:
* **Cleavage:** Peptides are often cleaved by specific proteases to generate smaller, functional peptides.
* **Glycosylation:** The attachment of sugar molecules to peptide chains.
* **Phosphorylation:** The addition of phosphate groups, influencing the peptide's activity.
* **Acetylation:** The addition of an acetyl group, often at the N-terminus.

3. **Peptide Degradation:** Peptides are broken down into their constituent amino acids through proteolysis. This is mediated by enzymes like peptidases and proteases.

4. **Peptide Transport:** Peptides are transported across cellular membranes by specific transporter proteins, enabling their movement into different cellular compartments or extracellular spaces.

5. **Peptide Function:** Peptides serve diverse roles, including:
* **Hormones and Growth Factors:** Peptides like insulin and growth hormone regulate various physiological processes.
* **Signal Transduction:** Peptides can act as ligands for cell surface receptors, triggering signaling cascades.
* **Immune Response:** Peptides from pathogens can stimulate the immune system, leading to an immune response.
* **Antimicrobial Agents:** Peptides can exhibit antimicrobial activity, inhibiting the growth of bacteria or viruses.

6. **Peptide Metabolism Regulation:** The peptide metabolic process is tightly regulated by various factors, including:
* **Gene expression:** The synthesis of enzymes involved in peptide metabolism is controlled by gene expression.
* **Cellular environment:** Factors like pH, temperature, and nutrient availability can influence peptide metabolism.

7. **Disruptions in Peptide Metabolism:** Dysregulation of peptide metabolism can contribute to a range of diseases, including:
* **Cancer:** Abnormalities in peptide growth factors can promote tumor growth.
* **Neurological Disorders:** Disruptions in neuropeptide metabolism can contribute to neurodegenerative diseases.
* **Immune Deficiency:** Defects in peptide-mediated immune responses can lead to immunodeficiency.

The peptide metabolic process is intricate and essential for maintaining cellular function and organismal health. Its complexity provides numerous targets for therapeutic intervention in various diseases.'
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Proteins (4)

Compounds (35)