Month: November 2018

Balancing Specificity and Promiscuity in Enzyme Evolution: Multidimensional Activity Transitions in the Alkaline Phosphatase Superfamily

Bert van Loo, Christopher D. Bayer, Gerhard Fischer, Stefanie Jonas, Eugene Valkov, Mark F. Mohamed, Anastassia Vorobieva, Celine Dutruel, Marko Hyvönen and Florian Hollfelder

Journal of American Chemical Society 141:370-387 (2019)
DOI: 10.1021/jacs.8b10290
Pubmed: 30497259

PDB coordinates:
4UPH (3D view), 4UPI (3D view), 4UPL (3D view), 4UPK (3D view)


Highly proficient, promiscuous enzymes can be springboards for functional evolution, able to avoid loss of function during adaptation by their capacity to promote multiple reactions. We employ a systematic comparative study of structure, sequence, and substrate specificity to track the evolution of specificity and reactivity between promiscuous members of clades of the alkaline phosphatase (AP) superfamily. Construction of a phylogenetic tree of protein sequences maps out the likely transition zone between arylsulfatases (ASs) and phosphonate monoester hydrolases (PMHs). Kinetic analysis shows that all enzymes characterized have four chemically distinct phospho- and sulfoesterase activities, with rate accelerations ranging from 1011- to 1017-fold for their primary and 109- to 1012-fold for their promiscuous reactions, suggesting that catalytic promiscuity is widespread in the AP-superfamily. Continue reading →

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A general approach for the site-selective modification of native proteins, enabling the generation of stable and functional antibody–drug conjugates

Stephen J. Walsh, Soleilmane Omarjee, Warren R. J. D. Galloway, Terence T.-L. Kwan, Hannah F. Sore, Jeremy S. Parker, Marko Hyvönen, Jason S. Carroll and David R. Spring

Chem. Sci., 2019,10, 694-700

DOI: 10.1039/C8SC04645J
Pubmed: 0774870


<Antibody–drug conjugates (ADCs) are a class of targeted therapeutics that utilize the specificity of antibodies to selectively deliver highly potent cytotoxins to target cells. Although recent years have witnessed significant interest in ADCs, problems remain with the standard linkage chemistries used for cytotoxin-antibody bioconjugation. These typically (1) generate unstable constructs, which may lead to premature cytotoxin release, (2) often give a wide variance in drug–antibody ratios (DAR) and (3) have poor control of attachment location on the antibody, resulting in a variable pharmacokinetic profile. Herein, we report a novel divinylpyrimidine (DVP) linker platform for selective bioconjugation via covalent re-bridging of reduced disulfide bonds on native antibodies. Continue reading →

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