Marc Garcia-Borràs

Marc Garcia-Borràs
University of California, Los Angeles | UCLA · Department of Chemistry and Biochemistry

PhD

About

99
Publications
12,372
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,847
Citations

Publications

Publications (99)
Article
New-to-nature radical biocatalysis has recently emerged as a powerful strategy to tame fleeting open-shell intermediates for stereoselective transformations. In 2021, we introduced a novel metalloredox biocatalysis strategy that leverages the innate redox properties of the heme cofactor of P450 enzymes, furnishing new-to-nature atom-transfer radica...
Article
Full-text available
Protein-ligand binding processes often involve changes in protonation states that can be key to recognize and orient the ligand in the binding site. The pathways through which (bio)molecules interplay to attain productively bound complexes are intricate and involve a series of interconnected intermediate and transition states. Molecular dynamics (M...
Article
The regioselective polyfunctionalization of highly symmetric spherical Ih-C60 is extremely challenging and usually leads to the formation of regioisomeric mixtures not amenable for high-pressure liquid chromatography (HPLC) purification. Here, we pioneer the use of tetragonal prismatic nanocapsules to perform selective Diels-Alder (DA) functionaliz...
Article
We report the reprogramming of nonheme iron enzymes to catalyze an abiological C(sp3)‒H azidation reaction through iron-catalyzed radical relay. This biocatalytic transformation uses amidyl radicals as hydrogen atom abstractors and Fe(III)‒N3 intermediates as radical trapping agents. We established a high-throughput screening platform based on clic...
Preprint
Full-text available
Catalysis with engineered enzymes has provided more efficient and streamlined routes for the synthesis and manufacturing of drug molecules. Despite landmark achievements, the potential of biocatalysis toward assisting early-stage drug discovery campaigns remains largely untapped. We have developed a novel biocatalytic strategy for the construction...
Preprint
Protein-ligand binding processes often involve changes in protonation states that can be key to recognize and orient the ligand in the binding site. The pathways through which (bio)molecules interplay to attain productively bound complexes are intricate and involve a series of interconnected intermediate and transition states. Molecular dynamics (M...
Preprint
The oxidation of alkenes by high-valent iron-oxo active species normally leads to the formation of the corresponding epoxides. Rarely, carbonyl compounds are observed as a side product of the reaction. However, the selective formation of carbonyl compounds from alkenes using iron-oxo species and small molecule catalysts has not yet been achieved. R...
Preprint
The regioselective poly-functionalization of highly symmetric spherical Ih-C60 is extremely challenging and usually leads to the formation of regio-isomeric mixtures not amenable for HPLC purification. Recently, we have pioneered the regioselective functionalization of C60 fullerene under a supramolecular mask strategy, using tetragonal prismatic n...
Preprint
Full-text available
The direct regioselective oxidation of internal alkenes to ketones could simplify synthetic routes and solve a longstanding challenge in synthesis. This reaction is of particular importance because ketones are predominant moieties in valuable products as well as crucial intermediates in synthesis. Here we report the directed evolution of a ketone s...
Article
Propargyl amines are versatile synthetic intermediates with numerous applications in the pharmaceutical industry. An attractive strategy for efficient preparation of these compounds is nitrene propargylic C(sp³)–H insertion. However, achieving this reaction with good chemo-, regio-, and enantioselective control has proven to be challenging. Here, w...
Article
Full-text available
Whereas enzymatic asymmetric carbene N–H insertion is a powerful method for preparation of chiral amines in principle, it has suffered from limited enantioselectivity in practice. In this work, we demonstrate that engineered cytochrome P450 enzymes can catalyze this abiological C–N bond-forming reaction with excellent activity and selectivity (up t...
Article
The mechanism by which molecular oxygen is activated by the organic cofactor pyridoxal phosphate (PLP) for oxidation reactions remains poorly understood. Recent work has identified arginine oxidases that catalyze desaturation or hydroxylation reactions. Here, we investigate a desaturase from the Pseudoalteromonas luteoviolacea indolmycin pathway. O...
Article
A high throughput GC-MS approach was developed, permitting the simultaneous analysis of up to three substrates and six products quantitatively from one reaction mixture. This screening approach was applied to site-saturation libraries of the novel unspecific peroxygenaseMthUPO. Using this setup enabled substantial insights from a small mutant libra...
Article
Full-text available
Decades of extensive research efforts by biochemists, organic chemists, and protein engineers have led to an understanding of the basic mechanisms of essentially all known types of enzymes, but in a formidable number of cases an essential aspect has been overlooked. The occurrence of short-lived chiral intermediates formed by symmetry-breaking of p...
Article
A cytochrome c heme protein was recently engineered to catalyze the formation of carbon-silicon bonds via carbene insertion into Si-H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity toward C-Si bond formation over competing C-N bond formation was achieved, although this trait was not screened for...
Preprint
p>Whereas enzymatic asymmetric carbene N–H insertion is a powerful method for preparation of chiral amines in principle, it has suffered from limited enantioselectivity in practice. In this work, we demonstrate that engineered cytochrome P450 enzymes can catalyze this abiological C–N bond-forming reaction with excellent activity and selectivity (up...
Preprint
div> Iterative P450 enzymes are powerful biocatalysts for selective late-stage C-H oxidation of complex natural product scaffolds. These enzymes represent new tools for selectivity and cascade reactions, facilitating direct access to core structure diversification. Recently, we reported the structure of the multifunctional bacterial P450 TamI and...
Article
Full-text available
Multidimensional fitness landscapes provide insights into the molecular basis of laboratory and natural evolution. To date, such efforts usually focus on limited protein families and a single enzyme trait, with little concern about the relationship between protein epistasis and conformational dynamics. Here, we report a multiparametric fitness land...
Preprint
div> A cytochrome c heme protein was recently engineered to catalyze the formation of carbon–silicon bonds via carbene insertion into Si–H bonds, a reaction that was not previously known to be catalyzed by a protein. High chemoselectivity towards C–Si bond formation over competing C–N bond formation was achieved, although this trait was not screen...
Article
Biocatalysis offers an expanding and powerful strategy to construct and diversify complex molecules by C─H bond functionalization. Due to their high selectivity, enzymes have become an essential tool for C─H bond functionalization and offer complementary reactivity to small-molecule catalysts. Hemoproteins, particularly cytochromes P450, have prove...
Article
Full-text available
Machine learning (ML) has pervaded most areas of protein engineering, including stability and stereoselectivity. Using limonene epoxide hydrolase as the model enzyme and innov’SAR as the ML platform, comprising a digital signal process, we achieved high protein robustness that may resist unfolding with concomitant detrimental aggregation. Fourier t...
Preprint
Biocatalysis offers an expanding and powerful strategy to construct and diversify complex molecules by C-H bond functionalization. Due to their high selectivity, enzymes have become an essential tool for C-H bond functionalization and offer complementary reactivity to small-molecule catalysts. Hemoproteins, particularly cytochromes P450, have prove...
Article
The tris- and tetra-adducts of [email protected] metallofullerenes were synthesized and characterized for the first time. The 1,3-dipolar cy-cloaddition (Prato reaction) of [email protected] and [email protected] with an excess of N-ethylglycine and formaldehyde provided tris- and tetra-fulleropyrrolidine adducts in a regioselective manner. Purific...
Article
Full-text available
Efficient regeneration of cofactors is vital for the establishment of biocatalytic processes. Formate is an ideal electron donor for cofactor regeneration due to its general availability, low reduction potential, and benign byproduct (CO2). However, formate dehydrogenases (FDHs) are usually specific to NAD⁺, such that NADPH regeneration with format...
Article
Full-text available
Steroidal C7β alcohols and their respective esters have shown significant promise as neuroprotective and anti‐inflammatory agents to treat chronic neuronal damage like stroke, brain trauma and cerebral ischemia. Since position C7 is spatially far away from any functional groups that could direct C–H activation, these transformations are not readily...
Preprint
Full-text available
Efficient regeneration of cofactors is vital for the establishment of continuous biocatalytic processes. Formate is an ideal electron donor for cofactor regeneration due to its general availability, low reduction potential, and benign byproduct (CO2). However, formate dehydrogenases (FDHs) are usual specific to NAD+, such that NADPH regeneration wi...
Article
Full-text available
Steroidal C7β alcohols and their respective esters have shown significant promise as neuroprotective and anti‐inflammatory agents to treat chronic neuronal damage like stroke, brain trauma and cerebral ischemia. Since position C7 is spatially far away from any functional groups that could direct C–H activation, these transformations are not readily...
Preprint
Compared to the biological world’s rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild-type cytochrome P450 monooxygenase (P450<sub>BM3 </sub>from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to make silanols. Directed evolutio...
Article
In rerum natura: Wild‐type cytochrome P450BM3 catalyzes the oxidation of hydrosilanes to silanols both in vivo and in vitro. Directed evolution was used to generate an efficient and selective biocatalyst that delivers a broad range of aryl‐ and alkyl‐substituted silanols. Computational studies revealed a sequence of H atom abstraction and OH reboun...
Article
Full-text available
Evolution has converged on cation-π interactions for recognition of quaternary alkyl ammonium groups such as trimethyllysine (Kme3). While computational modelling indicates that Trp provides the strongest cation-π interaction of the native aromatic amino acids, there is limited corroborative data from measurements within proteins. Herein we investi...
Article
Compared to the biological world’s rich chemistry for functionalizing carbon, enzymatic transformations of the heavier homologue silicon are rare. We report that a wild‐type cytochrome P450 monooxygenase (P450 BM3 from Bacillus megaterium, CYP102A1) has promiscuous activity for oxidation of hydrosilanes to make silanols. Directed evolution enhanced...
Article
Isomer-pure poly-functionalized fullerenes are required to boost the development of fullerene chemistry in all fields. On a general basis, multi-adduct mixtures with uncontrolled regioselectivity are obtained, and the use of chromatographic purification is prohibitively costly and time consuming, especially in the production of solar cells. Single-...
Article
Full-text available
Cytochromes P450 (P450s) are nature's catalysts of choice for performing demanding and physiologically vital oxidation reactions. Biochemical characterization of these enzymes over the past decades has provided detailed mechanistic insight and highlighted the diversity of substrates P450s accommodate and the spectrum of oxidative transformations th...
Article
Full-text available
LepI is an S-adenosylmethionine (SAM)-dependent pericyclase that catalyses the formation of the 2-pyridone natural product leporin C. Biochemical characterization has shown that LepI can catalyse stereoselective dehydration to yield a reactive (E)-quinone methide that can undergo bifurcating intramolecular Diels–Alder (IMDA) and hetero-Diels–Alder...
Article
The structures of two bis-ethylpyrrolidinoadducts of [email protected], obtained by regioselective 1,3-dipolar cycloadditions, were elucidated by single crystal X-ray, vis-NIR spectra, studies on their thermal isomerization, and theoretical calculations. The structure of the minor-bis-adduct reveals a C2-symmetric carbon cage with [6,6][6,6]-additi...
Article
Full-text available
Microbial conversion of aromatic compounds is an emerging and promising strategy for valorization of the plant biopolymer lignin. A critical and often rate-limiting reaction in aromatic catabolism is O -aryl-demethylation of the abundant aromatic methoxy groups in lignin to form diols, which enables subsequent oxidative aromatic ring-opening. Recen...
Article
Three Prato monoadduct isomers were synthesized and structurally characterized by 1H, 13C NMR spectra and single-crystal X-ray diffraction, and one adduct on the dd-[5,6]-bond was found as the first example of a Prato [5,6]-adduct of C70. To investigate the mechanism in the generation of this dd-[5,6]-adduct, computational studies were employed to...
Article
An entropic intermediate is defined as a free energy minimum that is not a potential energy minimum; the favorable entropy in this region of the potential surface is responsible for the increased lifetime of this species. Enabled by molecular dynamics simulations, entropic intermediates have been identified for several types of reactions, particula...
Article
Full-text available
Cytochrome P450 enzymes have gained significant interest as selective oxidants in late-stage chemical synthesis. Their broad substrate scope enables them to be good candidates for their use in non-natural reactivity. Directed evolution evolves new enzyme biocatalysts that promote alternative reactivity for chemical synthesis. While directed evoluti...
Article
We report an ambimodal trispericyclic transition state leading to [6+4]-, [4+6]-, and [8+2]-cycloadducts in the reactions of 8,8-disubstituted heptafulvenes with 6,6-dimethylfulvene. The potential energy surfaces for these reactions were explored with ωB97X-D density functional theory. Quasi-classical direct molecular dynamics simulations gave info...
Article
Novel naphthalene-based 5 •(BArF) 8 capsule allows for the size-selective inclusion of C 60 from fullerene mixtures. Its size selectivity towards C 60 has been rationalized by its dynamic adaptability in solution that has...
Preprint
LepI is an S-adenosylmethionine (SAM)-dependent pericyclase that catalyzes the formation of 2-pyridone natural product leporin C. Biochemical characterization showed LepI can catalyze the stereoselective dehydration to yield a reactive (E)-quinone methide which can undergo a bifurcating intramolecular Diels-Alder (IMDA) and hetero-Diels-Alder (HDA)...
Preprint
p> There are few biocatalytic transformations that produce fluorine-containing molecules prevalent in modern pharmaceuticals. To expand the scope of biocatalysis for organofluorine synthesis, we have developed an enzymatic platform for highly enantioselective carbene B–H bond insertion to yield versatile α- trifluoromethylated ( α -CF<sub>3</sub>)...
Article
There are few biocatalytic transformations that produce fluorine-containing molecules prevalent in modern pharmaceuticals. To expand the scope of biocatalysis for organofluorine synthesis, we have developed an enzymatic platform for highly enantioselective carbene B–H bond insertion to yield versatile α-trifluoromethylated (α-CF_3) organoborons, an...
Article
Manipulating the regioselectivity of Baeyer-Villiger (BV) reactions remains an ongoing issue in organic chemistry, be it by synthetic catalysts or enzymes of the type Baeyer-Villiger monooxygenases. Herein, we address the challenging problem of switching normal to abnormal BVMO regioselectivity by directed evolution using three linear ketones as su...
Article
Full-text available
Microbial aromatic catabolism offers a promising approach to convert lignin, a vast source of renewable carbon, into useful products. Aryl-O-demethylation is an essential biochemical reaction to ultimately catabolize coniferyl and sinapyl lignin-derived aromatic compounds, and is often a key bottleneck for both native and engineered bioconversion p...
Article
Recently, heme proteins have been discovered and engineered by directed evolution to catalyze chemical transformations that are biochemically unprecedented. Many of these nonnatural enzyme-catalyzed reactions are assumed to proceed through a catalytic iron porphyrin carbene (IPC) intermediate, although this intermediate has never been observed in a...
Article
Duclauxins are dimeric and heptacyclic fungal polyketides with significant bioactivities. We characterized the cascade of redox transformations in the biosynthesis of duclauxin pathway from Talaromyces stipitatus. The redox reaction sequence is initiated by a cupin family dioxygenase DuxM that performs an oxidative cleavage of the peri-fused tricyc...
Article
Full-text available
Hapalindole alkaloids are a structurally diverse class of cyanobacterial natural products defined by their varied polycyclic ring systems and diverse biological activities. These complex metabolites are generated from a common biosynthetic intermediate by the Stig cyclases in three mechanistic steps: a rare Cope rearrangement, 6-exo-trig cyclizatio...
Article
The conformational landscape of Bacillus megaterium epoxide hydrolase (BmEH) and how it is altered by mutations that confer the enzyme the ability to accept bulky epoxide substrates has been investigated. Extensive molecular dynamics (MD) simulations coupled to active site volume calculations have unveiled relevant features of the enzyme conformati...
Article
Electrides are ionic substances that present isolated electrons. These confined electrons are topologically characterised by a quasiatom, i.e. a non‐nuclear attractor (NNA) of the electron density. The electronic structure of octahedral 4A1g Li6+ and 5A1g Be6 species shows that these species have a large number of NNAs. These NNAs present highly de...
Article
Controlling the regioselectivity in the exohedral functionalization of fullerenes and endohedral metallofullerenes is essential to produce specific desired fullerene derivatives. In this work, using Density functional theory (DFT) calculations, we show that the regioselectivity of the Diels-Alder (DA) cycloaddition of cyclopentadiene to 2S+1C60 cha...
Article
Enzymes exist as ensembles of conformations that are important for function. Tuning these populations of conformational states through mutation enables evolution toward additional activities. Here we computationally evaluate the population shifts induced by distal and active site mutations in a family of computationally designed and experimentally...
Article
Full-text available
Epoxide hydrolases (EHs) enzymes catalyze the hydration of racemic epoxides to yield their corresponding vicinal diols. These enzymes present different enantio- and regioselectivity depending upon either the substrate structure or the substitution pattern of the epoxide ring. In this study, we computationally investigate the Bacillus megaterium epo...
Article
The first chemical modification on the brand new endohedral HF@C60 is reported. In particular, the isomerization from optically pure (2S,5S)-cis-pyrrolidino[3,4:1,2][60]fullerene 2b to (2S,5R)-trans-pyrrolidino[3,4:1,2][60]fullerene 2b has been studied and compared with empty C60 (2a) and endohedral H2O@C60 (3). Interestingly, the incarcerated HF m...
Preprint
Hapalindole alkaloids are a structurally diverse class of cyanobacterial natural products defined by their varied polycyclic ring systems and diverse biological activities. These polycyclic scaffolds are generated from a common biosynthetic intermediate by the Stig cyclases in three mechanistic steps, including a rare Cope-rearrangement, 6-exo-trig...
Article
Malbrancheamide is a dichlorinated fungal indole alkaloid isolated from Malbranchea aurantiaca that belongs to a family of natural products containing a characteristic bicyclo[2.2.2]diazaoctane core. The introduction of chlorine atoms on the indole ring of malbrancheamide differentiates it from other members of this family and contributes significa...
Article
In this review, we show that the local aromaticity of C60 and endohedral metallofullerenes (EMFs) is a key factor to understand and predict their structure and reactivity. We report recent examples provided by our group that highlight the importance of aromaticity in C60 and EMFs. First example discusses the regioselectivity of Diels-Alder reaction...
Article
Full-text available
The synthesis of endohedral metallofullerenes (EMFs) from a carbon soot sample of an arc discharge leads to a variety of EMFs that are obtained in different relative abundances. In the present work, we show that these abundances can be predicted from aromaticity calculations. In particular, we use the normalized Additive Local Aromaticity (ALAN) in...