Capping of biotinylated proteins in biological samples increases sensitivity of CCMS
Biotin, also known as vitamin H, is a water souble vitamin of the B-complex. It is composed of tetrahydromidizalone ring which is fused with a tetrahydrothiophene ring attached with a valeric acid substituent.
Biotin plays an important role in cell metabolism (e.g. synthesis of fatty acids, amino acids and gluconeogenesis). As a cofactor, biotin is used in carbondioxide transfer reactions by carboxylase enzymes (1).
All cells typically display some amount of naturally biotinylated proteins and enzymes. As the interaction of biotin and streptavidin with a Kd of ~1015 is one of the strongest non-covalent interactions (2) these proteins can potentially be detected as ´background noise´ when avidin or streptavidin based systems are employed to pull out artificially biotinylated proteins from cell lysates. The CCMS technology also relies on streptavidin magnetic particles for the final purification steps.
In order to suppress signals from naturally biotinylated proteins and to prevent a loss of sensitivity, caprotec has developed a straightforward solution to this issue: the Biotin Capping Kit.
This kit is using soluble streptavidin to bind naturally biotinylated proteins in biological samples and then saturates the free remaining biotin binding sites with a well balanced amount of free biotin. This system efficiently prevents the majority of background signal that can occur if samples with high degree of naturally biotinylated proteins are used as protein source in CCMS.
Please read the Application Note or Guideline to learn more about the Biotin Capping Kit.