Bioorganic Chemistry 2007-06-01

Synthesis and characterization of CN-modified protein analogues as potential vibrational contrast agents.

Matthew Noestheden, Qingyan Hu, Li-Lin Tay, Angela M Tonary, Albert Stolow, Roger MacKenzie, Jamshid Tanha, John Paul Pezacki

Index: Bioorg. Chem. 35(3) , 284-93, (2007)

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Abstract

A recombinant VH single-domain antibody recognizing staphylococcal protein A was functionalized on reactive lysine residues with N-hydroxysuccimidyl-activated 4-cyanobenzoate. Surface plasmon resonance analysis of antibody-antigen binding revealed that modified and unmodified antibodies bound protein A with similar affinities. Raman imaging of the modified antibodies indicated that the benzonitrile group provides vibrational contrast enhancement in a region of the electromagnetic spectrum that is transparent to cellular materials. Thus, the modified single-domain antibody may be amenable to detecting protein A from samples of the human pathogen Staphylococcus aureus using vibronic detection schemes such as Raman and coherent anti-Stokes Raman scattering. The generality of this labeling strategy should make it applicable to modifying an array of proteins with varied structure and function.