<h3>Title</h3>
<p><span style="color: #0000ff;">Chemical technologies for precision labeling of native proteins</span></p>
<p><strong><span style="text-decoration: underline;">Abstract</span> :</strong></p>
<p style="text-align: justify;">Single-site protein modification impacts diverse aspects of Science at the interface of biology, chemistry, biomaterials, and biologics. The prominent way to access such protein conjugates is through bio-synthetically pre-engineered proteins with un-natural amino acids or fragments. Unfortunately, these methods do not operate with native proteins leaving an enormous technological void. The solution to this challenge would require a chemical transformation that can allow single-site protein labeling, regulation of the site-of-labeling, and operate with multiple proteins. During my talk, I will present the chemical tools for precession engineering of proteins. The challenges related to reaction kinetics, chemoselectivity, and site-selectivity for single-site labeling of proteins will be addressed. These chemical methods can render site-selective N-terminus labeling of proteins and also can distinguish N-terminus residues for site-specific labeling. In particular, I would like to bring your attention to Gly-Tag® and Linchpin Directed Modification (LDM®) technologies that led to residue-specific labeling and site-selective labeling of proteins respectively. The native proteins can now be labeled with absolute precision enabled by a modular chemical platform (LDM®). The functional groups introduced by labeling open the potential for the orthogonal late-stage installation of an affinity tag, NMR tag, and a fluorophore. These chemical technologies are operationally simple, deliver ordered immobilization, and analytically pure probe tagged proteins. The LDM technology enabled the synthesis of homogeneous antibody-drug conjugates that exhibits highly specific antiproliferative activity toward HER-2 positive SKBR-3 breast cancer cells. Besides, I will discuss the first general method for chemoselective functionalization of serine residue which is rarely chosen as a handle for selective derivatization. Finally, I will end my talk with the development of new PSI-reagents that can render selective transformation of serine residue into Dha formation, a post-translational modification.</p>