Journal: ACS Nano

Article Title: A Hybrid Protein–Polymer Nanoworm Potentiates Apoptosis Better than a Monoclonal Antibody

doi: 10.1021/nn403973g

Figure Lengend Snippet: Purified scFv-A192 forms nanoparticles whose secondary structure is stabilized by renaturation. (a) Purified scFv-A192 on a 4–20% SDS-PAGE shows a MW of ∼99.6 kDa and a purity of 91.4 ± 1.3%. Outlined lanes were used to determine protein purity using ImageJ. (b) scFv-A192 assembles nanoparticles with a hydrodynamic radius of 85.7 ± 16.5 nm. (c) Changes in protein structure during refolding were characterized by circular dichroism, which show a significant shift in spectra at 190 and 220 nm. (d) Deconvolution of the curves showed a substantial decrease in β-turn 2 content. The lowering of the β-turn content suggests a change in the ELP secondary structure.

Article Snippet: Precast 4–20% SDS PAGE gels were purchased from Lonza (Basel, Switzerland).

Techniques: Purification, SDS Page, Circular Dichroism

Journal: Protein Science : A Publication of the Protein Society

Article Title: Elastin‐like polypeptide switches: A design strategy to detect multimeric proteins

doi: 10.1002/pro.3215

Figure Lengend Snippet: Identification of a high molecular weight ELP that detects streptavidin‐biotin interactions. (A) SDS‐PAGE confirmed the identity and purity of an ELP, 2VA192 (Table I). (B) Optical density was used to characterize the concentration‐temperature phase diagrams for a library of ELPs with increasing chain lengths. ELPs phase separate above the indicated best‐fit lines. (C) Similarly, biotin‐2VA192 (biotin‐ELP) with and without a stoichiometric ratio of streptavidin [4:1] was characterized. The best‐fit line and its 95% confidence interval are depicted.

Article Snippet: ELP was filtered using 200 nm cellulose acetate filters (28145–477, VWR, Radnor, PA) and concentration was estimated using Beer‐Lambert's law at A280 using 1285 M−1cm−1 as the molar extinction coefficient.35 Purity and identity was determined by loading 5 μg ELP in SDS loading buffer, heating at 95°C for 5 min, and running on a 4–20% gradient Tris‐Glycine SDS PAGE gel (58505, Lonza, Walkersville, MD).

Techniques: High Molecular Weight, SDS Page, Concentration Assay