New methodologies for site-specifically radiolabeling proteins with the PET isotope [.sup.1SF] are required to generate high quality radiotracers for imaging in both the preclinical and clinical settings. The enzymatic radiofluorination overcomes many of the limitations encountered to date with purely chemical approaches. The bacterial enzyme lipoic acid ligase was used to conjugate [.sup.18F]-fluorooctanoic acid to both a small peptide and a Fab antibody fragment. Labeling was site-specific and highly efficient under mild aqueous conditions using small amounts of peptide/protein (1-10 nmol). The labeled construct retained full epitope binding affinity and was stable in mouse serum. Using an optimized reaction scheme, mCi quantities of [.sup.18F]-Fab were generated, an amount sufficient for human imaging.

The present disclosure is generally related to transformed host cells and their use for the production of branched-chain acyl-ACPs, branched-chain acyl-ACP-derived chemicals and fuels, branched-chain fatty acids and producing branched-chain fatty acid-derived chemicals and fuels. More particularly, disclosed herein are transformed host cells and methods for producing branched-chain acyl-ACPs and branched-chain fatty acids in high titer and high percentages. Also disclosed are methods for producing specific branched-chain fatty acid species and producing branched-chain fatty acid-derived chemicals and fuels such as, for example, branched-chain alcohols and branched-chain fatty acid ethyl esters.

An exemplary embodiment of the present disclosure provides a method of converting formate to a desired compound. The method comprises providing a biocatalyst and formate to form a reaction mixture and reacting at least the biocatalyst with formate to produce a first reaction product.

It has been found, surprisingly, that the Corynebacterium humireducens strain comprises a very effective glycine cleavage system.