The buffer power of plasma proteins: experimental observations are consistent while the definitions are not

The human body utilizes protein buffer systems to maintain a stable pH. These systems capitalize on the dual role of amino acids, which can act as acids or bases by accepting or releasing hydrogen ions in response to pH changes. Protein buffer systems are particularly significant in the extracellular fluid (ECF) and intracellular fluid (ICF) of active cells, where structural and functional proteins provide substantial buffering capacity.
Certain amino acids can exist in a zwitterion state at a...

Drugs predominantly attach to plasma proteins, with only a small percentage remaining unbound. The unbound portion can be calculated as one minus the bound fraction. Acidic drugs form large, inactive complexes by reversibly binding to plasma albumin, which prevents them from diffusing across biological barriers. These drug-protein complexes act as reservoirs for the drugs. As the concentration of unbound drugs decreases, these complexes quickly dissociate to release the free drug, maintaining...

The equilibrium binding constant (Kb) quantifies the strength of a protein-ligand interaction. Kb can be calculated as follows when the reaction is at equilibrium:

Blood plasma is a fluid that contains approximately 92% water and 8% solutes. The solutes include various types of proteins, which constitute about 7% of the total solutes in the plasma. The high-molecular-weight proteins—albumins, globulins, and fibrinogen—are essential to plasma function. Albumins, making up about 60% of the plasma proteins, maintain the osmotic balance within blood vessels by preventing excessive water leakage. Additionally, albumins serve as carrier proteins,...

Physiological models with protein binding in pharmacokinetics offer a sophisticated approach to understanding drug disposition. These models consider drug-protein interactions, enabling them to effectively predict drug concentrations in different organs and tissues. This precision aids in accurate drug dosing, providing a significant advantage over conventional models. A key process within these models is equilibration, which ensures that drug concentrations achieve a steady state within the...

Buffer solutions do not have an unlimited capacity to keep the pH relatively constant . Instead, the ability of a buffer solution to resist changes in pH relies on the presence of appreciable amounts of its conjugate weak acid-base pair. When enough strong acid or base is added to substantially lower the concentration of either member of the buffer pair, the buffering action within the solution is compromised.
The buffer capacity is the amount of acid or base that can be added to a given volume...