140kDa

140 kDa refers to a molecular weight of 140 kilodaltons. A dalton (Da) is a unit of mass commonly used for atoms and molecules, especially proteins. One kilodalton is equal to 1,000 daltons. Therefore, 140 kDa represents a mass of 140,000 daltons. This measurement is frequently encountered in biochemistry and molecular biology, particularly when describing the size of proteins.

Proteins are composed of amino acids, and the mass of a protein is determined by the number and type of amino acids in its sequence. The molecular weight of a protein is a key characteristic used for its identification and characterization. For instance, when analyzing proteins using techniques like gel electrophoresis, their migration patterns are often related to their size, and thus their molecular weight. A protein with a molecular weight of 140 kDa would be considered a relatively large protein. Many enzymes, structural proteins, and signaling molecules fall within this size range. For example, some subunits of important cellular machinery, like ribosomal proteins or certain components of the cytoskeleton, can have molecular weights around this value. The precise molecular weight is crucial for understanding a protein's function, its interactions with other molecules, and its behavior within biological systems.