Elucidating the Impact of Payload Conjugation on the Cell-Penetrating Efficiency of the Endosomal Escape Peptide dfTAT: Implications for Future Designs for CPP-Based Delivery Systems.

Cell-penetrating peptides (CPPs) are promising tools for the intracellular delivery of various biological payloads. However, the impact of payload conjugation on the cell-penetrating activity of CPPs is poorly understood. This study focused on dfTAT, a modified version of the HIV-TAT peptide with enhanced endosomal escape activity, to explore how different payloads affect its cell-penetrating activity. We systematically examined dfTAT conjugated with the SnoopTag/SnoopCatcher pair and found that while smaller payloads such as short peptides do not significantly impair dfTAT's cell delivery activity, larger payloads markedly reduce both its endocytic uptake and endosomal escape efficiency. Our results highlight the role of the payload size and bulk in limiting CPP-mediated delivery. While further research is needed to understand the molecular underpinnings of these effects, our findings pave the way for developing more effective CPP-based delivery systems.

Complete Genome Sequence of Stenotrophomonas maltophilia Podophage Paxi.

Stenotrophomonas maltophilia is a multidrug-resistant nosocomial pathogen that can cause life-threatening infections among immunocompromised populations. This report presents the complete 74,962-bp genome of S. maltophilia podophage Paxi, an N4-like phage sharing 85.3% nucleotide similarity to S. maltophilia podophage Pokken.

Complete Genome Sequence of Klebsiella aerogenes Siphophage Solomon.

Klebsiella aerogenes is a bacterium that can cause a variety of infections. Phage-based biotechnologies may be useful for controlling antibiotic-resistant strains of this bacterium. The characterization of K. aerogenes phage Solomon is described here. Solomon has a 51,775-bp genome, with structural components closely resembling those of Escherichia coli siphophage T1.