Arada, H.; Yamaguchi, H.

Chem. Commun. 2020, 56, 1605-1607, 10.1039/c9cc08756g

We report the first preparation of a monoclonal antibody (mAb) that can immobilize a palladium (Pd)-complex. The allylic amination reaction using a supramolecular catalyst of the Pd-complex with mAb selectively gives the (R)-enantiomer product.

Harada, A.; Yamaguchi, H.

Sci. Rep. 2019, 9, 10.1038/s41598-019-49844-0

Design and engineering of protein scaffolds are crucial to create artificial metalloenzymes. Herein we report the first example of C-C bond formation catalyzed by artificial metalloenzymes, which consist of monoclonal antibodies (mAbs) and C2 symmetric metal catalysts. Prepared as a tailored protein scaffold for a binaphthyl derivative (BN), mAbs bind metal catalysts bearing a 1,1?-bi-isoquinoline (BIQ) ligand to yield artificial metalloenzymes. These artificial metalloenzymes catalyze the Friedel-Crafts alkylation reaction. In the presence of mAb R44E1, the reaction proceeds with 88% ee. The reaction catalyzed by Cu-catalyst incorporated into the binding site of mAb R44E1 is found to show excellent enantioselectivity with 99% ee. The protein environment also enables the use of BIQ-based catalysts as asymmetric catalysts for the first time.

Ebright, R.H.; Gunasekeram, A.

Proc. Natl. Acad. Sci. U. S. A. 1990, 87, 2882-2886, 10.1073/pnas.87.8.2882

Escherichia coli catabolite gene activator protein (CAP) is a helix-turn-helix motif sequence-specific DNA binding protein [de Crombrugghe, B., Busby, S. & Buc, H. (1984) Science 224, 831-838; and Pabo, C. & Sauer, R. (1984) Annu. Rev. Biochem. 53, 293-321]. In this work, CAP has been converted into a site-specific DNA cleavage agent by incorporation of the chelator 1,10-phenanthroline at amino acid 10 of the helix-turn-helix motif. [(N-Acetyl-5-amino-1,10-phenanthroline)-Cys178]CAP binds to a 22-base-pair DNA recognition site with Kobs = 1 x 10(8) M-1. In the presence of Cu(II) and reducing agent, [(N-acetyl-5-amino-1,10-phenanthroline)-Cys178]CAP cleaves DNA at four adjacent nucleotides on each DNA strand within the DNA recognition site. The DNA cleavage reaction has been demonstrated using 40-base-pair and 7164-base-pair DNA substrates. The DNA cleavage reaction is not inhibited by dam methylation of the DNA substrate. Such semisynthetic site-specific DNA cleavage agents have potential applications in chromosome mapping, cloning, and sequencing.

Keinan, E.

Pure Appl. Chem. 1990, 62, 2013-2019, 10.1351/pac199062102013

An attempt was made to mimic cytochrome P-450-like activity using antibodies elicited against metallo-porphyrins. Monoclonal antibodies raised against a water-soluble Sn(1V) porphyrin complex (1) exhibited Specificity for a variety of monomeric metalloporphyrins, as well as for the b-0x0-Fe(III) porphyrin dimer 2. Some antibodies were found to be more selective for the monomer 1 than for the dimer 2, suggesting an "edge-on" recognition of the planar porphyrin molecule. The catalytic activity of the antibody-metalloporphyrin complexes was investigated using the epoxidation of styrene by iodosobenzene as a model reaction. Three biphasic media were studied for this reaction: reverse micelles, microemulsions, and solid catalyst in organic solvent. The most promising results were obtained with solid catalyst (obtained via lyophilization of equimolar amounts of Mn(TCP)Cl and specific antibody) in dry CHzClz at room temperature, as indicated by the high turnover numbers of the catalyst. A difference in the relative activity of the various monoclonal antibodies (MABs) was noted. The anti-1 antibodies displayed ca. 30-60% higher activity compared to a nonrelevant MAB.