A Site-Selective Dual Anchoring Strategy for Artificial Metalloprotein Design

• Published in: Journal of the American Chemical Society Vol. 126; no. 35; pp. 10812 - 10813
• Main Authors: Carey, James R, Ma, Steven K, Pfister, Thomas D, Garner, Dewain K, Kim, Hyeon K, Abramite, Joseph A, Wang, Zhilin, Guo, Zijian, Lu, Yi
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 08.09.2004; Amer Chemical Soc
• Subjects: Animals; Apoproteins - chemistry; Apoproteins - metabolism; Binding Sites; Biological and medical sciences; Biomimetic Materials - chemical synthesis; Biomimetic Materials - chemistry; Biomimetic Materials - metabolism; Chemistry; Chemistry, Multidisciplinary; Chromium - chemistry; Cytochrome-c Peroxidase - chemistry; Cytochrome-c Peroxidase - metabolism; Ethylenediamines - chemistry; Ethylenediamines - metabolism; Fundamental and applied biological sciences. Psychology; Heme - chemistry; Heme - metabolism; Heme - physiology; Interactions. Associations; Intermolecular phenomena; Metalloproteins - chemical synthesis; Metalloproteins - chemistry; Metalloproteins - metabolism; Models, Molecular; Molecular biophysics; Myoglobin - chemistry; Myoglobin - metabolism; Organometallic Compounds - chemistry; Organometallic Compounds - metabolism; Physical Sciences; Science & Technology; Spectrophotometry, Ultraviolet; Stereoisomerism; PROTEIN; APOMYOGLOBIN; SPERM-WHALE MYOGLOBIN; ENZYMES; HYBRID CATALYSTS; STRUCTURAL-CHARACTERIZATION; METALLOENZYMES; DIRECTED EVOLUTION; SULFHYDRYL GROUPS; EPOXIDATION; Binding capacity; Manganese Complexes; Organic ligand; Molecular interaction; Molecular aggregation; Transition metal Complexes; Metalloproteins; Ultraviolet visible spectrometry
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja046908x

Introducing nonnative metal ions or metal-containing prosthetic groups into a protein can dramatically expand the repertoire of its functionalities and thus its range of applications. Particularly challenging is the control of substrate-binding and thus reaction selectivity such as enantioselectivity. To meet this challenge, both non-covalent and single-point attachments of metal complexes have been demonstrated previously. Since the protein template did not evolve to bind artificial metal complexes tightly in a single conformation, efforts to restrict conformational freedom by modifying the metal complexes and/or the protein are required to achieve high enantioselectivity using the above two strategies. Here we report a novel site-selective dual anchoring (two-point covalent attachment) strategy to introduce an achiral manganese salen complex (Mn(salen)), into apo sperm whale myoglobin (Mb) with bioconjugation yield close to 100%. The enantioselective excess increases from 0.3% for non-covalent, to 12.3% for single point, and to 51.3% for dual anchoring attachments. The dual anchoring method has the advantage of restricting the conformational freedom of the metal complex in the protein and can be generally applied to protein incorporation of other metal complexes with minimal structural modification to either the metal complex or the protein.