Biology subjects

Yue, G.

Publications and source records attributed to Yue, G..

5 recordsLinked to original sources

bioRxiv2021

Mapping the allosteric effects that define functional activity of SARS-CoV-2 specific antibodies

Previous studies on the structural relationship between human antibodies and SARS-CoV-2 have focused on generating static snapshots of antibody complexes with the Spike trimer. However, antibody-antigen interactions are dynamic, with significant binding-induced allosteric effects on conformations of antibody and its target antigen. In this study, we employ hydrogen-deuterium exchange mass spectrometry, in vitro assays, and molecular dynamics simulations to investigate the allosteric perturbations linked to binding events between a group of human antibodies with differential functional activities, and the Spike trimer from SARS-CoV-2. Our investigations have revealed key dynamic features that define weakly or moderately neutralizing antibodies versus those with strong neutralizing activity. These results provide mechanistic insights into the functional modes of human antibodies against COVID-19, and provide a rationale for effective antiviral strategies. TeaserDifferent neutralizing antibodies induce site-specific allosteric effects across SARS-CoV-2 Spike protein

biochemistry↗

bioRxiv2021

The SPEECHLESS-induced stomatal increase is required for the salt tolerance of oil palm

Oil palm is the most productive oil producing plant. Salt stress leads to growth damage and decrease in yield of oil palm. However, the physiological responses of oil palm to salt stress and their underlying mechanisms are not clear. RNA-Seq for leaf samples from young palms challenged under three levels of salts (100, 250 and 500 mM NaCl) and control for 14 days was conducted. Diverse signalling pathways were involved in responses to different levels of salt stress. All the three levels of salt stress activated EgSPCH expression and induced stomatal density of oil palm, which was contrasting to that in Arabidopsis. Under strong salt stress group, oil palm removed excessive salt via stomata. Overexpression of EgSPCH in Arabidopsis increased the stomatal production but lowered the salt tolerance. These data suggest that in oil palm, salt activates EgSPCH to generate more stomata in response to salt stress. Our results shed a light on the cellular response to salt stress of oil palm and provide new insights into the mechanisms of different salt-induced stomatal development between halophytes and glycophytes.

plant biology↗

bioRxiv2021

Direct precise measurement of the stall torque of the flagellar motor in E. coli

The flagellar motor drives the rotation of flagellar filaments, propeling the swimming of flagellated bacteria. The maximum torque the motor generates, the stall torque, is a key characteristics of the motor function. Direct measurements of the stall torque carried out three decades ago suffered from large experimental uncertainties, and subsequently there were only indirect measurements. Here, we applied magnetic tweezer to directly measure the stall torque in E. coli. We precisely calibrated the torsional stiffness of the magnetic tweezer, and performed motor resurrection experiments at stall, accomplishing a precise determination of the stall torque per torque-generating unit (stator unit). From our measurements, each stator passes 2 protons per step, indicating a tight coupling between motor rotation and proton flux.

biophysics↗

bioRxiv2021

Exploring the Interactome of Cytochrome P450 2E1 in Human Liver Microsomes with Chemical Cross-Linking Mass Spectrometry

Aiming to elucidate the grounds of system-wide effects of the alcohol-induced increase in the content of cytochrome P450 2E1 (CYP2E1) on drug metabolism, we explored the array of its protein-protein interactions (proteome) in human liver microsomes (HLM) with chemical crosslinking mass spectrometry (CXMS). Our strategy employs membrane incorporation of purified CYP2E1 modified with photoreactive crosslinkers benzophenone-4-maleimide (BPM) and 4-(N-succinimidylcarboxy)benzophenone (BPS). Exposure of bait-incorporated HLM samples to light was followed by isolating the His-tagged bait protein and its crosslinked aggregates on Ni-NTA agarose. Analyzing the individual bands of SDS-PAGE slabs of thereby isolated protein with the toolset of untargeted proteomics, we detected the crosslinked dimeric and trimeric complexes of CYP2E1 with other drug-metabolizing enzymes. Among the most extensively crosslinked partners of CYP2E1 are the cytochromes P450 2A6, 2C8, 3A4, 4A11, and 4F2. Of particular interest are the interactions of CYP2E1 with the latter two enzymes, which are involved in the synthesis and disposal of vasoactive and pro-inflammatory eicosanoids. We also detected the conjugates of CYP2E1 with UDP-glucuronosyltransferases (UGTs) 1A and 2B, fatty aldehyde dehydrogenase (ALDH3A2), epoxide hydrolase 1 (EPHX1), disulfide oxidase 1 (ERO1L), and ribophorin II (RPN2). These results demonstrate the exploratory power of the proposed CXMS strategy and corroborate the concept of tight functional integration in the human drug-metabolizing ensemble through protein-protein interactions of the constituting enzymes.

biochemistry↗

bioRxiv2020

SARS-CoV-2 S protein ACE2 interaction reveals novel allosteric targets

The Spike (S) protein is the main handle for SARS-CoV-2 to enter host cells through surface ACE2 receptors. How ACE2 binding activates proteolysis of S protein is unknown. Here, we have mapped the S:ACE2 interface and uncovered long-range allosteric propagation of ACE2 binding to sites critical for viral host entry. Unexpectedly, ACE2 binding enhances dynamics at a distal S1/S2 cleavage site and flanking protease docking site ~27 [A] away while dampening dynamics of the stalk hinge (central helix and heptad repeat) regions ~ 130 [A] away. This highlights that the stalk and proteolysis sites of the S protein are dynamic hotspots in the pre-fusion state. Our findings provide a mechanistic basis for S:ACE2 complex formation, critical for proteolytic processing and viral-host membrane fusion and highlight protease docking sites flanking the S1/S2 cleavage site, fusion peptide and heptad repeat 1 (HR1) as allosterically exposed cryptic hotspots for potential therapeutic development. One Sentence SummarySARS-CoV-2 spike protein binding to receptor ACE2 allosterically enhances furin proteolysis at distal S1/S2 cleavage sites

biochemistry↗