Protein C is a protein in plasma that enters into the cascade of biochemical events leading to the formation of a clot. Deficiency of protein C results in thrombotic (clotting) disease and excess platelets with recurrent thrombophlebitis (inflammation of the vein that occurs when a clot forms). The clot can break loose and travel through the blood stream (thromboembolism) to the lungs causing a pulmonary embolism, brain causing a stroke (cerebrovascular accident), heart causing an early heart attack, skin causing what in the newborn is called neonatal purpura fulminans, the adrenal gland causing hemorrhage with abdominal pain, abnormally low blood pressure (hypotension), and salt loss. Protein C deficiency is due to possession of one gene (heterozygosity) in chromosome band 2q13-14. The possession of two such genes (homozygosity) is usually lethal.
- Protein kinase A
An enzyme system that is activated by cyclic adenosine monophosphate (cAMP) and that catalyzes the activity of intracellular proteins. There are two isozymes of protein kinase A, type I and type II. Also known as cAMP-dependent protein kinase and cyclic AMP-dependent protein kinase.
- Protein malnutrition
Insufficient intake of nitrogen-containing food (protein) to maintain a nitrogen balance or nitrogen equilibrium. Children are particularly prone to develop protein malnutrition. To grow, children have to consume enough nitrogen-containing food (protein) to maintain a positive nitrogen balance, whereas adults need only be in nitrogen equilibrium. See also kwashiorkor.
- Protein requirements, infant
Proteins contain different amino acids that are linked together. Proteins provide both calories and the amino acid building blocks that are necessary for proper growth. The protein in human milk provides between 10%-15% of an infant’s daily caloric need. Casein and whey are the two major proteins of human milk and most milk-based formulas. (Immunoglobulins, […]
- Protein ZIP code
An informal name for a molecular cell biology system of signals or “address tags” that guide the movement of a protein within a cell. In more technical terms, protein ZIP codes* are molecular signals that direct the protein from the endoplasmic reticulum, where it is assembled, to the cytoplasm of the cell and into other […]
A condition in which there is excessive loss of plasma protein into the intestine. Protein-losing enteropathy can be due to a number of different causes including extensive ulceration of the intestine, intestinal lymphatic blockage, gluten enteropathy, and infiltration of leukemic cells into the intestinal wall.