Thiol-reactive linkers are chemical compounds designed to react specifically with thiol groups (-SH) found in antibodies, proteins, peptides, and other biomolecules. These linkers are commonly used to covalently attach other molecules-such as drugs, fluorescent labels, or other functional groups-to the target biomolecules. Applications include antibody-drug conjugate (ADC) synthesis, protein labeling, and crosslinking studies.
In biological systems, thiols often exist in the form of disulfide bonds (-S-S-), which are not reactive toward thiol-reactive linkers. Only free or reduced sulfhydryl groups (-SH) are available for conjugation.
Common thiol-reactive functional groups include:
These functional groups enable site-specific modification of biomolecules and are critical in designing targeted and stable bioconjugates.