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Inamdar, K.

Publications and source records attributed to Inamdar, K..

4 recordsLinked to original sources

A Growth-Based Framework for Scaling Infant Anthropometry in Motion Capture Studies

Biomechanical analysis of infant motor behavior is complicated by rapid growth and large inter-subject variability in body size and segment proportions. We present a growth-adjusted anthropometric scaling framework that integrates Centers for Disease Control and Prevention (CDC) growth charts with three-dimensional motion capture to estimate subject-specific infant biomechanics during prone play. Nineteen infants aged 2-6 months were recorded during spontaneous prone movement. Weight-for-age percentiles were computed using CDC LMS parameters and used to infer body length from length-for-age references, ensuring internal consistency between weight and length estimates. Body segments were scaled using published infant proportions and validated against head and shoulder widths measured from motion capture. Infant head and trunk proportions were substantially larger than adult values, whereas limb proportions were similar. Estimated and measured dimensions of head and trunk width showed good agreement, with mean root mean squared errors of approximately 3 cm. Adult-based scaling produced head and trunk length errors of up to 6 cm. This growth-adjusted framework improves anatomical fidelity and enables normalization of biomechanical measures across infants with differing growth trajectories.

bioengineering↗

Self-blinking dye restores efficient use of nanobodies in single-molecule localization microscopy.

Direct stochastic optical reconstruction microscopy (dSTORM) relies on controlled fluorophore blinking to achieve nanometer-scale resolution, yet the fields benchmark dye, Alexa Fluor 647, underperforms when conjugated to nanobodies, limiting the practical use of minimal-linkage labeling strategies. Here, we show that the self-blinking dye JF635b overcomes this limitation by maintaining robust, photostable blinking upon conjugation to nanobodies under buffer-independent conditions. This enables reliable single-molecule localization microscopy without the need for complex switching buffers. Using JF635b-labeled nanobodies, we demonstrate consistent performance across multiple imaging modalities, including wide-field dSTORM, fluorescence lifetime SMLM, and MINFLUX nanoscopy, achieving localization precisions from [~]15 nm down to the sub-nanometer regime. In addition, JF635b supports long-term sample preservation and efficient blinking even in pure water, enabling minimally perturbative imaging conditions. Together, these results establish self-blinking dSTORM as a robust and accessible platform for quantitative nanoscopy across experimental contexts.

biophysics↗

Direct optical measurement of intra-molecular distances down to the Angstrom scale

Optical investigations of nanometer distances between proteins, their subunits, or other biomolecules have been the exclusive prerogative of Forster Resonance Energy Transfer (FRET) microscopy for decades. Here we show that MINFLUX fluorescence nanoscopy measures intra-molecular distances down to 1 nm - and in planar projections down to 1 Angstrom - directly, linearly, and with Angstrom precision. Our method is validated by quantifying well-characterized 1-to-10 nm distances in polypeptides and proteins. Moreover, we visualize the orientations of immunoglobulin subunits and reveal specific configurations of a histidine kinase domain dimer. Our results open the door for examining proximities and interactions of macromolecules under physiological conditions.

biophysics↗

Full assembly of HIV-1 particles requires assistance of the membrane curvature factor IRSp53.

During HIV-1 particle formation, the requisite plasma membrane curvature is thought to be solely driven by the retroviral Gag protein. Here, we reveal that the cellular I-BAR protein IRSp53 is required for the progression of HIV-1 membrane curvature to complete particle assembly. Partial gene editing of IRSp53 induces a decrease in viral particle production and a viral bud arrest at half completion. Single molecule localization microscopy at the cell plasma membrane shows a preferential localization of IRSp53 around HIV-1 Gag assembly sites. In addition, we observe the presence of IRSp53 in purified HIV-1 particles. Finally, HIV-1 Gag protein localizes preferentially to IRSp53 I-BAR domain induced curved membranes on giant unilamellar vesicles. Overall, our data reveal a strong interplay between IRSp53 I-BAR and Gag at membranes during virus assembly. This highlights IRSp53 as a crucial host factor in HIV-1 membrane curvature and its requirement for full HIV-1 particle assembly.

biophysics↗