alanine metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving alanine, 2-aminopropanoic acid. [GOC:go_curators]

Alanine metabolism is a crucial biological process that involves the breakdown, synthesis, and interconversion of the amino acid alanine. This process plays a significant role in various physiological functions, including:

**1. Gluconeogenesis:** Alanine can be converted into glucose in the liver through a process called gluconeogenesis. This is particularly important during fasting or prolonged exercise when glucose levels are low.

**2. Energy Production:** Alanine can be catabolized to produce energy in the form of ATP. This process involves the removal of the amino group from alanine, followed by conversion to pyruvate, which enters the citric acid cycle for energy generation.

**3. Muscle Protein Metabolism:** Alanine plays a role in muscle protein turnover. During exercise, muscle proteins are broken down to provide energy. The released amino acids, including alanine, are transported to the liver where they can be used for gluconeogenesis or energy production.

**4. Nitrogen Transport:** Alanine serves as a carrier for nitrogen from muscle to the liver. This is important for removing excess nitrogen from the body, which is a byproduct of protein breakdown.

**5. Interorgan Nitrogen Transfer:** Alanine is involved in the transfer of nitrogen between different organs. For instance, it can be transferred from muscle to the liver or from the intestines to other tissues.

**Enzymatic Reactions Involved:**

**1. Alanine Transaminase (ALT):** This enzyme catalyzes the reversible transfer of an amino group from alanine to α-ketoglutarate, producing pyruvate and glutamate. ALT is primarily found in the liver and is used to assess liver function.

**2. Alanine Aminotransferase (AAT):** This enzyme catalyzes the reversible transfer of an amino group from alanine to pyruvate, producing α-ketoglutarate and glutamate.

**3. Alanine Dehydrogenase:** This enzyme catalyzes the oxidative deamination of alanine to pyruvate and ammonia.

**Regulation of Alanine Metabolism:**

Alanine metabolism is tightly regulated by various factors, including:

**1. Insulin:** Insulin promotes alanine uptake and synthesis.

**2. Glucagon:** Glucagon stimulates alanine release from muscle.

**3. Cortisol:** Cortisol promotes gluconeogenesis and increases alanine production.

**4. Dietary Intake:** Protein intake influences alanine levels in the body.

**Clinical Significance:**

**1. Liver Disease:** Abnormal levels of alanine transaminase (ALT) in the blood can indicate liver damage.

**2. Muscle Disorders:** Elevated alanine levels can be associated with muscle wasting conditions.

**3. Diabetes:** Impaired alanine metabolism can contribute to hyperglycemia in individuals with diabetes.

**4. Cancer:** Some types of cancer cells exhibit increased alanine metabolism, contributing to their growth and survival.'"

Proteins (1)

Compounds (1)