Protein Shape-Shifting in Fatty Acid Biosynthesis
In a recent study, researchers at the Dalian Institute of Chemical Physics have provided a detailed look at how the acyl carrier protein (ACP) – a central component of fatty acid biosynthesis – changes its shape in response to the length of the fatty acid chains it carries. Using native mass spectrometry and ultraviolet photodissociation (UVPD), the team examined ACP molecules bound to fatty acids ranging in length from C4 to C18, allowing them to track how the protein’s internal structure adapts.
They found that shorter chains (up to C10) sit within a primary hydrophobic cavity, while longer chains bend and extend into a secondary pocket. Specific amino acids, including Phe50 and Ile62, appear to act as gates that shift to accommodate these structural changes. Other flexible regions in the protein, such as Loop I and a Thr64–Gln66 segment, played a role in stabilizing the binding of longer acyl chains.
"Our study provides molecular‐level insight into how ACP adapts to acyl chains of different lengths," said Wang Fangjun, the study’s lead author. "The findings set the stage for the rational redesign of ACP to enhance the biosynthesis of target fatty acids, particularly medium‐chain species (C8-C12) with high industrial value."
A New Way to Study Tannins in Food and Drink
Tannins, the complex polyphenols behind the astringency or smoothness of wine, chocolate, and many fruits, have long been measurable in bulk but difficult to link to specific sensory effects. A new study in the Journal of Agricultural and Food Chemistry by Penn State researchers introduces Condensed Tannin Fragmentation Fingerprinting – a method to identify and quantify individual procyanidins, the molecular building blocks of many tannins, offering a clearer connection between tannin structure and mouthfeel.
The team used in-source fragmentation to break apart large, complex tannin molecules into predictable ion patterns, enabling the researchers to determine the makeup of tannin mixtures in various samples by comparing these patterns to reference standards. They validated their method on prepared mixtures and then applied it to commercial cider products. The results were consistent and repeatable, allowing them to distinguish among different procyanidin profiles.
“We wanted to understand the biological activity of taste and mouthfeel, but this goes beyond taste and mouthfeel,” commented senior author Misha Kwasniewsk. "Procyanidins also are responsible for antioxidant activity and health-related benefits, and current analytical methods often show a lack of correlation with biological activities and health-related benefits.”
The researchers are now collaborating with winemakers in Pennsylvania to apply their technique in vineyards and cellars. Understanding tannin profiles at a detailed level could help producers refine wine styles through grape selection and fermentation techniques.
Strips, Spots, and Spectrometers: Fighting Malaria with Paper
In a transformative field trial in Ghana, scientists from Ohio State University have unveiled a low-cost, paper-based diagnostic device that detects malaria in asymptomatic individuals with remarkable precision. Consisting of layered, wax-treated paper strips embedded with chemical reagents and ionic probes, the device exceeds traditional diagnostics such as microscopy, rapid diagnostic tests, and PCR – achieving a sensitivity of 96.5%,.
A single drop of blood triggers a sequence of reactions, isolating a malaria-specific antigen that can be identified using a handheld mass spectrometer. The entire process takes about 30 minutes and requires no refrigeration, making it particularly well suited to remote or resource-limited settings.
“Typically you would take the sample to the lab, but now we are taking the lab to the sample,” said lead author Abraham Badu-Tawiah in a recent press release. Beyond malaria, the team is exploring how this diagnostic platform could be adapted to detect other diseases by simply switching out the antibody targets – potentially opening up rapid, field-deployable screening for colorectal cancer, acute pancreatitis, and other diseases.
Can We Trust Our Protein Discovery Pipelines?
A new study from researchers at the University of Washington and the University of Sydney has examined how well current proteomics software tools control the false discovery rate (FDR) – a statistical threshold commonly set to limit erroneous identifications. The analysis, published in Nature Methods, focuses on evaluating tools used in both data-dependent (DDA) and data-independent acquisition (DIA) workflows.
The researchers systematically applied a benchmarking approach known as entrapment, where synthetic or foreign peptide sequences are inserted into the search database but excluded from the true biological sample. Any detection of these sequences signals a false discovery. Additionally, the study introduces a new method, paired estimation, to yield more reliable assessments of FDR control. This approach pairs real and synthetic peptides one-to-one, enabling a clearer picture of how often algorithms misidentify peptides or proteins.
When applied across a range of datasets and search engines, the results showed that most DDA tools generally maintained valid FDR control at the peptide level. In contrast, several widely used DIA tools, including DIA-NN, Spectronaut, and EncyclopeDIA, frequently failed to control the FDR at the protein level. This discrepancy was especially notable in challenging scenarios such as single-cell proteomics, where the rate of false positives rose substantially.
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