TY  - JOUR
AB  - The human enzyme p97 regulates various cellular pathways by unfolding hundreds of protein substrates in an ATP-dependent manner, making it an essential component of protein homeostasis and an impactful pharmacological target. The hexameric complex undergoes substantial conformational changes throughout its catalytic cycle. Here we elucidate the molecular motions that occur at the active site in the temporal window immediately before and after ATP hydrolysis by merging cryo-EM, NMR spectroscopy and molecular dynamics simulations. p97 populates a metastable reaction intermediate, the ADP·Pi state, which is poised between hydrolysis and product release. Detailed snapshots reveal that the active site is finely tuned to trap and eventually discharge the cleaved phosphate. Signalling pathways originating at the active site coordinate the action of the hexamer subunits and couple hydrolysis with allosteric conformational changes. Our multidisciplinary approach enables a glimpse into the sophisticated spatial and temporal orchestration of ATP handling by a prototype AAA+ protein.
AU  - Shein, M.
AU  - Hitzenberger, M.*
AU  - Cheng, T.C.*
AU  - Rout, S.R.*
AU  - Leitl, K.
AU  - Sato, Y.*
AU  - Zacharias, M.*
AU  - Sakata, E.*
AU  - Schütz, A.K.
C1  - 69950
C2  - 55333
CY  - Heidelberger Platz 3, Berlin, 14197, Germany
SP  - 363-372
TI  - Characterizing ATP processing by the AAA+ protein p97 at the atomic level.
JO  - Nat. Chem.
VL  - 16
IS  - 3
PB  - Nature Portfolio
PY  - 2024
SN  - 1755-4330
ER  - 

TY  - JOUR
AB  - High-resolution, multiplexed experiments are a staple in cellular imaging. Analogous experiments in animals are challenging, however, due to substantial scattering and autofluorescence in tissue at visible (350-700 nm) and near-infrared (700-1,000 nm) wavelengths. Here, we enable real-time, non-invasive multicolour imaging experiments in animals through the design of optical contrast agents for the shortwave infrared (SWIR, 1,000-2,000 nm) region and complementary advances in imaging technologies. We developed tunable, SWIR-emissive flavylium polymethine dyes and established relationships between structure and photophysical properties for this class of bright SWIR contrast agents. In parallel, we designed an imaging system with variable near-infrared/SWIR excitation and single-channel detection, facilitating video-rate multicolour SWIR imaging for optically guided surgery and imaging of awake and moving mice with multiplexed detection. Optimized dyes matched to 980 nm and 1,064 nm lasers, combined with the clinically approved indocyanine green, enabled real-time, three-colour imaging with high temporal and spatial resolutions.
AU  - Cosco, E.
AU  - Spearman, A.L.*
AU  - Ramakrishnan, S.
AU  - Lingg, J.G.P.
AU  - Saccomano, M.
AU  - Pengshung, M.*
AU  - Arus, B.A.
AU  - Wong, K.C.Y.*
AU  - Glasl, S.
AU  - Ntziachristos, V.
AU  - Warmer, M.
AU  - McLaughlin, R.R.*
AU  - Bruns, O.T.
AU  - Sletten, E.M.*
C1  - 60458
C2  - 49465
CY  - Heidelberger Platz 3, Berlin, 14197, Germany
SP  - 1123-1130
TI  - Shortwave infrared polymethine fluorophores matched to excitation lasers enable non-invasive, multicolour in vivo imaging in real time.
JO  - Nat. Chem.
VL  - 12
IS  - 12
PB  - Nature Research
PY  - 2020
SN  - 1755-4330
ER  -