This invention discloses a high-affinity chimeric
peptide sensor and a
ubiquitin detection method and kit, belonging to the field of biodetection technology. To address the problems of
low affinity and poor selectivity in existing
ubiquitin detection tools, this invention obtains a V1091L
mutant of the HDAC6 ZnF fragment through multidimensional
mutagenesis, and integrates other
ubiquitin-binding domains using AI and
computer simulation to construct a chimeric
peptide sensor. Its Kd with monoubiquitin is less than 50 nM, and it can specifically bind some free ubiquitin. This invention also provides a detection method based on this sensor, enabling the detection of free ubiquitin and total ubiquitin through direct or competitive assays. It can calculate the amount of conjugated ubiquitin, determine deubiquitinase activity, and screen ubiquitin pathway regulators. A kit incorporating this sensor is also provided. The sensor of this invention exhibits high affinity and
high selectivity, and the detection method requires no complex instruments, making it suitable for complex biological samples and high-
throughput detection. It can also distinguish intact free ubiquitin in serum, providing a new tool for basic ubiquitin research and clinical detection, and has significant application value.