James C. Weisshaar

University of Wisconsin–Madison

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Trends

Author Order

Document Type

Co-Authors

Heejun Choi

Janelia Research Campus

Somenath Bakshi

University of Cambridge

Erik Richard

University of Colorado Boulder

Kueih‐Tzu Lu

National Synchrotron Radiation Research Center

Mainak Mustafi

Columbia University

Benjamin P. Bratton

Princeton University

Robert A. Walker

Montana State University

Yan‐Yu Zhu

Liaoning Normal University

Scott D. Hanton

Air Products (United States)

Gregory C. Eiden

Idaho National Laboratory

Cooperative Institutions

University of Wisconsin–Madison

Madison Group (United States)

University of California, Berkeley

Lawrence Berkeley National Laboratory

Centre National de la Recherche Scientifique

National Institute of Standards and Technology

University of Colorado Boulder

University of California System

National Institutes of Health

University of Wisconsin System

Author Statistics

Papers

Citation

H-Index

i-10 index

Research Field

Detailed granule motion within actin cortex of PC-12 cells

Michael Konopka James C. Weisshaar

Granule (geology)

Source

Cite

Citations (0)

Understanding Spatiotemporal Aspects of Cecropin a Attack on Single, Live Bacteria using Time-Lapse Fluorescence Microscopy

Biophysical Journal (2018)

Anurag Agrawal James C. Weisshaar

Cecropin

10.1016/j.bpj.2017.11.572

Cite

Citations (0)

Productive Hemifusion Intermediates in Fast Vesicle Fusion Driven by Neuronal SNAREs

Biophysical Journal (2007)

Tingting Liu Tingting Wang Edwin R. Chapman James C. Weisshaar

Vesicle fusion

Kiss-and-run fusion

SNAP25

Phosphatidylethanolamine

10.1529/biophysj.107.107896

Cite

Citations (52)

Vibronic spectrum of cold, gas-phase allyl radicals by multiphoton ionization

The Journal of Physical Chemistry (1987)

Andrew D. Sappey James C. Weisshaar

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVibronic spectrum of cold, gas-phase allyl radicals by multiphoton ionizationAndrew D. Sappey and James C. WeisshaarCite this: J. Phys. Chem. 1987, 91, 14, 3731–3736Publication Date (Print):July 1, 1987Publication History Published online1 May 2002Published inissue 1 July 1987https://pubs.acs.org/doi/10.1021/j100298a004https://doi.org/10.1021/j100298a004research-articleACS PublicationsRequest reuse permissionsArticle Views141Altmetric-Citations38LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Icon

Broad spectrum

10.1021/j100298a004

Cite

Citations (44)

ChemInform Abstract: Barriers to Internal Rotation in Substituted Toluenes and Their Cations: Effects of Electronic Excitation and Ionization

ChemInform (1998)

Erik Richard K. T. Lu Randy A. Walker James C. Weisshaar

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

10.1002/chin.199832346

Cite

Citations (0)

Cytoplasmic Protein Mobility in Osmotically Stressed Escherichia coli

Journal of Bacteriology (2008)

Michael Konopka Kem A. Sochacki Benjamin P. Bratton Irina A. Shkel M. Thomas Record

Facile diffusion of globular proteins within a cytoplasm that is dense with biopolymers is essential to normal cellular biochemical activity and growth. Remarkably, Escherichia coli grows in minimal medium over a wide range of external osmolalities (0.03 to 1.8 osmol). The mean cytoplasmic biopolymer volume fraction ((phi)) for such adapted cells ranges from 0.16 at 0.10 osmol to 0.36 at 1.45 osmol. For cells grown at 0.28 osmol, a similar phi range is obtained by plasmolysis (sudden osmotic upshift) using NaCl or sucrose as the external osmolyte, after which the only available cellular response is passive loss of cytoplasmic water. Here we measure the effective axial diffusion coefficient of green fluorescent protein (D(GFP)) in the cytoplasm of E. coli cells as a function of (phi) for both plasmolyzed and adapted cells. For plasmolyzed cells, the median D(GFP) (D(GFP)(m)) decreases by a factor of 70 as (phi) increases from 0.16 to 0.33. In sharp contrast, for adapted cells, D(GFP)(m) decreases only by a factor of 2.1 as (phi) increases from 0.16 to 0.36. Clearly, GFP diffusion is not determined by (phi) alone. By comparison with quantitative models, we show that the data cannot be explained by crowding theory. We suggest possible underlying causes of this surprising effect and further experiments that will help choose among competing hypotheses. Recovery of the ability of proteins to diffuse in the cytoplasm after plasmolysis may well be a key determinant of the time scale of the recovery of growth.

Plasmolysis

Macromolecular Crowding

10.1128/jb.00536-08

Cite

Citations (106)

Simultaneous Binding of Multiple EF-Tu Copies to Translating Ribosomes in Live Escherichia coli

mBio (2018)

Mainak Mustafi James C. Weisshaar

In bacteria, elongation factor Tu is a translational cofactor that forms ternary complexes with aminoacyl-tRNA (aa-tRNA) and GTP. Binding of a ternary complex to one of four flexible L7/L12 units on the ribosome tethers a charged tRNA in close proximity to the ribosomal A site. Two sequential tests for a match between the aa-tRNA anticodon and the current mRNA codon then follow. Because one elongation cycle can occur in as little as 50 ms and the vast majority of aa-tRNA copies are not cognate with the current mRNA codon, this testing must occur rapidly. We present a single-molecule localization and tracking study of fluorescently labeled EF-Tu in live

EF-Tu

Ternary complex

10.1128/mbio.02143-17

Cite

Citations (34)

Subdiffraction-Limit Study of Kaede Diffusion and Spatial Distribution in Live Escherichia coli

Biophysical Journal (2011)

Somenath Bakshi Benjamin P. Bratton James C. Weisshaar

Nucleoid

Particle (ecology)

Mean squared displacement

10.1016/j.bpj.2011.10.013

Cite

Citations (73)

Modified Pearson correlation coefficient for two-color imaging in spherocylindrical cells

BMC Bioinformatics (2018)

Sonisilpa Mohapatra James C. Weisshaar

The revolution in fluorescence microscopy enables sub-diffraction-limit ("superresolution") localization of hundreds or thousands of copies of two differently labeled proteins in the same live cell. In typical experiments, fluorescence from the entire three-dimensional (3D) cell body is projected along the z-axis of the microscope to form a 2D image at the camera plane. For imaging of two different species, here denoted "red" and "green", a significant biological question is the extent to which the red and green spatial distributions are positively correlated, anti-correlated, or uncorrelated. A commonly used statistic for assessing the degree of linear correlation between two image matrices R and G is the Pearson Correlation Coefficient (PCC). PCC should vary from - 1 (perfect anti-correlation) to 0 (no linear correlation) to + 1 (perfect positive correlation). However, in the special case of spherocylindrical bacterial cells such as E. coli or B. subtilis, we show that the PCC fails both qualitatively and quantitatively. PCC returns the same + 1 value for 2D projections of distributions that are either perfectly correlated in 3D or completely uncorrelated in 3D. The PCC also systematically underestimates the degree of anti-correlation between the projections of two perfectly anti-correlated 3D distributions. The problem is that the projection of a random spatial distribution within the 3D spherocylinder is non-random in 2D, whereas PCC compares every matrix element of R or G with the constant mean value [Formula: see text] or [Formula: see text]. We propose a modified Pearson Correlation Coefficient (MPCC) that corrects this problem for spherocylindrical cell geometry by using the proper reference matrix for comparison with R and G. Correct behavior of MPCC is confirmed for a variety of numerical simulations and on experimental distributions of HU and RNA polymerase in live E. coli cells. The MPCC concept should be generalizable to other cell shapes.

Fisher transformation

Partial correlation

10.1186/s12859-018-2444-3

Cite

Citations (32)

Localization and Tracking of Single RNA Polymerase Molecules in Live E. Coli

Biophysical Journal (2014)

Somenath Bakshi James C. Weisshaar

Nucleoid

Transcription

Transcription bubble

RNA polymerase II

10.1016/j.bpj.2013.11.4466

Cite

Citations (0)