A5087504421- Glycosylation and Glycoproteins Research
- Carbohydrate Chemistry and Synthesis
- Chemical Synthesis and Analysis
- Enzyme Production and Characterization
- RNA and protein synthesis mechanisms
- Click Chemistry and Applications
- Biofuel production and bioconversion
- Monoclonal and Polyclonal Antibodies Research
- Protein Structure and Dynamics
- Biochemical and Structural Characterization
- Enzyme Structure and Function
- Microbial Metabolic Engineering and Bioproduction
- Polysaccharides and Plant Cell Walls
- Peptidase Inhibition and Analysis
- Ubiquitin and proteasome pathways
- Animal Virus Infections Studies
- Microtubule and mitosis dynamics
- Protein Kinase Regulation and GTPase Signaling
- Cyclopropane Reaction Mechanisms
- Advanced biosensing and bioanalysis techniques
- RNA modifications and cancer
- Machine Learning in Bioinformatics
- Transgenic Plants and Applications
- SARS-CoV-2 and COVID-19 Research
- Synthetic Organic Chemistry Methods
Chinese Academy of Medical Sciences & Peking Union Medical College
2019-2024
Zhejiang University
2024
Institute of Biophysics
2024
Peking Union Medical College Hospital
2020-2022
Academy of Medical Sciences
2020
University of Colorado Boulder
2013-2019
University of Colorado System
2015-2018
Infrafrontier
2015
Kettering University
2006-2012
Memorial Sloan Kettering Cancer Center
2007-2011
Proteins are made from 19 aa and, curiously, one N-alkylamino acid ("imino acid"), proline (Pro). Pro is thought to be incorporated by the translation apparatus at same rate as aa, even though alkyl group in resides directly on nitrogen nucleophile involved peptide bond formation. Here, combining quench-flow kinetics and charging of tRNAs with cognate noncognate amino acids, we find that incorporates significantly more slowly than Phe or Ala other acids incorporate much slowly. Our results...
Although the universal genetic code exhibits only minor variations in nature, Francis Crick proposed 1955 that “the adaptor hypothesis allows one to construct, theory, codes of bewildering variety.” The existing has been expanded enable incorporation a variety unnatural amino acids at or two nonadjacent sites within protein by using nonsense frameshift suppressor aminoacyl-tRNAs (aa-tRNAs) as adaptors. However, strategy is inherently limited compatibility with small subset codons, ways such...
Plant cell-wall polysaccharides represent a vast source of food in nature. To depolymerize to soluble sugars, many organisms use multifunctional enzyme mixtures consisting glycoside hydrolases, lytic polysaccharide mono-oxygenases, lyases, and carbohydrate esterases, as well accessory, redox-active enzymes for lignin depolymerization. Many these that degrade lignocellulose are multimodular with carbohydrate-binding modules (CBMs) catalytic domains connected by flexible, glycosylated linkers....
Native chemical ligation (NCL) is widely applicable for building proteins in the laboratory. Since discovery of this method, many strategies have been developed to enhance its capability and efficiency. Because poor reactivity proline thioesters, at a C-terminal site not readily accomplished. Here, we demonstrate that an N-terminal protein feasible using combined logic NCL metal-free dethiylation (MFD).
Significance Glycosylation is a ubiquitous posttranslational modification of proteins wherein carbohydrates are appended to protein side chains, with myriad functions in molecular and cell biology. The enzymes that break down polysaccharides other recalcitrant polymers nature often decorated two canonical forms glycosylation, N- O-linked glycans, the roles which only partially understood these key enzyme families importance both natural biomass turnover industrial biotechnology. Here, we...
In nature, enzymes that deconstruct biological polymers, such as cellulose and chitin, often exhibit multi-domain architectures, comprising a catalytic domain non-catalytic binding module; the latter serves to increase enzyme concentration at substrate surface. This architecture has been shown improve hydrolysis of poly(ethylene terephthalate) (PET) using engineered cutinase enzymes. Here, we examine role accessory modules industrially relevant PET solids loadings necessary for...
Maximizing by minimizing: An efficient and broadly useful two-step ligation protocol was developed. Important mechanistic issues of were probed from competition studies on the formation diastereomeric products. This study provides a valuable approach to facilitate polypeptide synthesis minimizing protecting group manipulations intermediate isolations. Detailed facts importance specialist readers are published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...
Application of native chemical ligation logic to the case an N-terminal proline is described. Two approaches were studied. One involved incorporation a 3R-substituted thiyl-proline derivative. Improved results obtained from selenol function, incorporated in context oxidized dimer.
Significance Plant biomass decomposition has broad implications for the global carbon cycle, agriculture, and ecology, it is primarily accomplished by fungi. Recently, research into fungal degradation mechanisms been driven growing biofuels industry, because enzymes from fungi are among primary catalysts being investigated industrial processes to convert polysaccharides upgradeable sugars. Understanding used polysaccharide-degrading identifying means improve their performance of paramount...
Using a pure Escherichia coli translation system, we tested the intrinsic specificity of protein biosynthetic machinery by determining relative yields peptide synthesis for incorporation series acyl-%@mt;sys@%tRNA%@sx@%GAC%@be@%AsnB%@sxx@%%@mx@% 's with varied backbone structures at sense codon GUU (Val). The results showed that different amino acids on same tRNA adaptor give significantly and potential cross-talk between acid body/anticodon in aa-tRNA decoding ribosome. They further support...
As simple as A, B, C: Non-cysteine-based reiterative fragment coupling of glycopeptides involves a metal-free (TCEP) peptidyl C-terminal phenolic ester containing an ortho-disulfide moiety (A) with N-terminal glycopeptide whose C terminus is alkyl thioester (B) to produce AB, N contains thioester. A AgCl-mediated AB peptide then produces the tridomainal ABC. TCEP=tris(2-carboxyethyl)phosphine. Supporting information for this article available on WWW under...
The power of chemical synthesis large cysteine-free polypeptides has been significantly enhanced through the use nonproteogenic constructs which bear strategically placed thiol groups, enabling native ligation. Central to these much expanded capabilities is specific, radical-induced, metal-free dethiolation, can be accomplished in aqueous medium.
Single erythropoietin (EPO) glycoforms with defined mature oligosaccharide structures and amino acid sequences are essential to elucidate the molecular mechanisms by which carbohydrates exert various physiological metabolic functions explore possible links between prevention or management of diseases. To demonstrate that it is generate EPO even without recourse cysteine-based native chemical ligation, a concise synthesis partially protected fragment (78-166) bearing fully N- O-glycans described.
The Ala1−Gly28 glycopeptide fragment (28) of EPO was prepared by chemical synthesis as a single glycoform. Key steps in the include attachment complex dodecasaccharide (7) to seven amino acid peptide via Lansbury aspartylation, native ligation join 19 with domain 18, and selective desulfurization at site reveal natural Ala19. This contains both requisite N-linked C-terminal αthioester handle, latter feature permitting direct coupling bearing N-terminal Cys29 without further functionalization.
The conversion of peptide and proteins from their soluble state into well-organized aggregates, together with the accompanied oxidation methionine residue, presents a significant challenge to human health, manufacture protein therapeutics, synthesis glycoproteins. Despite fundamental importance, little is known about molecular basis these two side reactions control. Here, using chemical synthesis, we further confirmed importance balance between hydrophobic interactions electrostatic...
Abstract The pandemic of SARS-CoV-2 has caused a high number deaths in the world. To combat it, it is necessary to develop better understanding how virus infects host cells. Infection normally starts with attachment cell-surface glycans like heparan sulfate (HS) and sialic acid-containing oligosaccharides. In this study, we examined compared binding subunits spike (S) proteins SARS-CoV, MERS-CoV these glycans. Our results revealed that S can bind HS sulfation-dependent manner, length not...
Described herein is the chemical synthesis of Cys29−Gly77 glycopeptide domain (22) erythropoietin. Our initial ligation strategy targeted a C → N termini condensation between 3 and peptide 4. However, reaction was hindered by "unattainable" reactivity, mismatched polarity, severe aggregation (glyco)peptide substrates. In contrast, tuning C-terminal acyl donor using smaller fragments, erythropoietin prepared through unconventional reactions. The use p-cyanonitrophenyl ester development masked...
We examine the specificity of translation for various primary and secondary amino acid analogues. A synthetase-free, pure, E. coli system is used to prevent competing reactions, three different tRNA adaptor:codon pairs are control tRNA- codon-specific effects. Surprisingly, N-butyl acids fail incorporate, N-methyl incorporation efficiencies dependent on adaptor, yet hydroxyPro, Pro, Phe, Ala incorporate near quantitatively from all adaptors. This suggests that Pro a privileged N-alkyl by...
Human galanin-like peptide (hGALP) is a newly discovered hypothalamic that plays important roles in the regulation of food intake and energy balance. Here, we demonstrate aspartic acid ligation can be employed to achieve an efficient synthesis hGALP. The total hGALP enhances our ability study its biology facilitates development more stable analogues.