Genetic encoding and enzymatic deprotection of a latent thiol side chain to enable new protein bioconjugation applications

Disulfide bonds play an important role in protein folding and stability. However, the cross-linking of sites within proteins by cysteine disulfides has significant distance and dihedral angle constraints. Here we report the genetic encoding of noncanonical amino acids containing long side-chain thiols that are readily incorporated into both bacterial and mammalian proteins in good yields and with excellent fidelity. These amino acids can pair with cysteines to afford extended disulfide bonds and allow cross-linking of more distant sites and distinct domains of proteins. To demonstrate this notion, we preformed growth-based selection experiments at nonpermissive temperatures using a library of random β-lactamase mutants containing these noncanonical amino acids. A mutant enzyme that is cross-linked by one such extended disulfide bond and is stabilized by ∼9 °C was identified. This result indicates that an expanded set of building blocks beyond the canonical 20 amino acids can lead to proteins with improved properties by unique mechanisms, distinct from those possible through conventional mutagenesis schemes.

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New protein reveals secrets of bacterial cell cycle

Nature India ◽

10.1038/nindia.2015.99 ◽

2015 ◽

Keyword(s):

Cell Cycle ◽

Bacterial Cell ◽

Bacterial Cell Cycle ◽

New Protein

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Electroluminescent properties of side-chain naphthalimide-derivated polymers

Journal de Chimie Physique ◽

10.1051/jcp:1998281 ◽

1998 ◽

Vol 95 (6) ◽

pp. 1351-1354 ◽

Cited By ~ 1

Author(s):

C.-M. Bouché ◽

P. Le Barny ◽

H. Facoetti ◽

F. Soyer ◽

P. Robin

Keyword(s):

Side Chain

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New 6-Bromotryptamine Derivatives from Marine Bacterium Pseudoalteromonas rubra QD1 - 2 and the Impact of Side Chain Length on Their Cytotoxicity

Planta Medica ◽

10.1055/s-0033-1348634 ◽

2013 ◽

Vol 79 (10) ◽

Author(s):

S He ◽

L Ding ◽

X Yan

Keyword(s):

Chain Length ◽

Marine Bacterium ◽

Side Chain ◽

Side Chain Length ◽

The Impact ◽

Pseudoalteromonas Rubra

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Evidence for Impaired Hepatic Vitamin K1 Metabolism in Patients Treated with N-Methyl-Thiotetrazole Cephalosporins

Thrombosis and Haemostasis ◽

10.1055/s-0038-1661101 ◽

1984 ◽

Vol 51 (03) ◽

pp. 358-361 ◽

Cited By ~ 78

Author(s):

H Bechtold ◽

K Andrassy ◽

E Jähnchen ◽

J Koderisch ◽

H Koderisch ◽

...

Keyword(s):

Protein C ◽

Oral Intake ◽

Bleeding Complications ◽

Side Chain ◽

Acute Administration ◽

Vitamin K1 ◽

New Class ◽

Parenteral Alimentation ◽

Hepatocellular Regeneration ◽

Echis Carinatus

SummaryIn 8 patients on no oral intake and with parenteral alimentation, administration of cephalosporins with N-methyl-thiotetrazole side chain (moxalactam, cefamandole), was associated with prolongation of prothrombin time, appearance in the circulation of descarboxy-prothrombin (counter immunoelectrophoresis and echis carinatus assay) and diminution of protein C. Acute administration of 10 mg vitamin Ki was followed by the transient appearance of vitamin K1 2,3-epoxide, indicating an impaired hepatocellular regeneration of vitamin K1 from the epoxide. Impaired hepatic vitamin K1 metabolism, tentatively ascribed to the N-methyl-thiotetrazole group, is one (but possibly not the only) cause of bleeding complications and depression of vitamin K1dependent procoagulants in patients treated with the new class of cephalosporins.

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Direct Molecular Fishing of New Protein Partners for Human Thromboxane Synthase

Acta Naturae ◽

10.32607/2075-8251-2017-9-4-92-100 ◽

2017 ◽

Vol 9 (4) ◽

pp. 92-100 ◽

Cited By ~ 5

Author(s):

A. V. Svirid ◽

◽

P. V. Ershov ◽

E. O. Yablokov ◽

L. A. Kaluzhskiy ◽

...

Keyword(s):

Thromboxane Synthase ◽

Protein Partners ◽

Molecular Fishing ◽

New Protein

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METABOLISM OF 17α-HYDROXYPROGESTERONE-4-14C-17α-CAPROATE BY HOMOGENATES OF RAT LIVER AND HUMAN PLACENTA

Acta Endocrinologica ◽

10.1530/acta.0.0360511 ◽

1961 ◽

Vol 36 (4) ◽

pp. 511-519 ◽

Cited By ~ 6

Author(s):

Margaret Wiener ◽

Charles I. Lupa ◽

E. Jürgen Plotz

Keyword(s):

Rat Liver ◽

Human Placenta ◽

Steric Hindrance ◽

Placental Tissue ◽

Caproic Acid ◽

Major Product ◽

Side Chain ◽

Anaerobic Conditions ◽

Prolonged Action ◽

Long Acting

ABSTRACT 17α-hydroxyprogesterone-4-14C-17α-caproate (HPC), a long-acting progestational agent, was incubated with homogenates of rat liver and human placenta. The rat liver was found to reduce Ring A of HPC under anaerobic conditions to form allopregnane-3β,17α-diol-20-one-17α-caproate and pregnane-3β,17α-diol-20-one-17α-caproate, the allopregnane isomer being the major product. The caproic acid ester was neither removed nor altered during the incubation. Placental tissue did not attack HPC under conditions where the 20-ketone of progesterone was reduced. It is postulated that this absence of attack on the side chain is due to steric hindrance from the caproate ester, and that this may account for the prolonged action of HPC.

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