Expanding the Genetic Code for a Dinitrophenyl Hapten

• Published in: Chembiochem : a European journal of chemical biology Vol. 16; no. 14; pp. 2007 - 2010
• Main Authors: Ren, Wei, Ji, Ao, Wang, Michael X., Ai, Hui-wang
• Format: Journal Article
• Language: English
• Published: WEINHEIM Blackwell Publishing Ltd 21.09.2015; Wiley; Wiley Subscription Services, Inc
• Subjects: Amino acids; Amino Acyl-tRNA Synthetases - genetics; Bacteriology; Biochemistry & Molecular Biology; Chemistry, Medicinal; Dinitrobenzenes - chemistry; Dinitrobenzenes - immunology; dinitrophenyl; Escherichia coli; Genetic Code; genetic code expansion; Genetic Engineering; haptens; Haptens - chemistry; Haptens - genetics; Haptens - immunology; HEK293 Cells; Humans; Life Sciences & Biomedicine; Lysine - analogs & derivatives; Lysine - chemistry; Lysine - genetics; Lysine - immunology; Methanosarcina barkeri; Methanosarcina barkeri - enzymology; Methanosarcina barkeri - genetics; Pharmacology & Pharmacy; Science & Technology; unnatural amino acids; ANTIBODIES; haptens; unnatural amino acids; TRANSFER-RNA SYNTHETASE; AFFINITY MATURATION; dinitrophenyl; AMINO-ACIDS; genetic code expansion; PROTEINS; BINDING
• ISSN: 1439-4227; 1439-7633
• DOI: 10.1002/cbic.201500204

Haptens, such as dinitrophenyl (DNP) are small molecules that induce strong immune responses when attached to proteins or peptides and, as such, have been exploited for diverse applications. We engineered a Methanosarcina barkeri pyrrolysyl‐tRNA synthetase (mbPylRS) to genetically encode a DNP‐containing unnatural amino acid, N6‐(2‐(2,4‐dinitrophenyl)acetyl)lysine (DnpK). Although this moiety was unstable in Escherichia coli, we found that its stability was enhanced in mammalian HEK 293T cells and was able to induce selective interactions with anti‐DNP antibodies. The capability of genetically introducing DNP into proteins is expected to find broad applications in biosensing, immunology, and therapeutics. Something unnatural about it: A dinitrophenyl (DNP)‐containing unnatural amino acid was genetically encoded for the preparation of hapten‐labeled proteins. This small hapten moiety was able to induce selective interactions with anti‐DNP antibodies. The capability of genetically introducing DNP into proteins has potential for applications in biosensing and bioseparation, immunology, and therapeutics.