Colloquium with Paul Ja nsen from ASML Research and Zainab Rashid, Physics of Living Systems, VU Amsterdam
12:30 - 12:50 Zainab Rashid, PostDoc, Ph ysics of Living Systems, VU Amsterdam
Title: T AV2b Peptide Derivatives Underwind and Stabilize Double- Stranded RNA upon Binding
Abstract: Double-strand ed RNA (dsRNA) has become an essential tool to understand biological processes with promising therapeutic implications. However, its usage is often limited due to poor cellular uptake and instability in biol ogical settings. Peptidic dsRNA binders, inspired by natural RNA-bind ing proteins, have emerged as promising tools to address these limita tions. However, it remains unclear how these peptides recognize RNA a nd impact its mechanical properties. Here we employed single-molecule magnetic tweezers to investigate TAV2b-derived peptidic dsRNA binder s. We showed that these peptides underwind dsRNA upon binding and sta bilize the resulting dsRNA conformation. Additionally, the wild-type peptide increases the dsRNA contour length while significantly loweri ng the persistence length. In contrast, a high-affinity homodimeric d erivative condenses the dsRNA tether at forces below 1 pN.
Furt hermore, real-time experiments performed to understand the binding me chanism of TAV2b-derived peptides showed that the wild-type derivativ e is in dynamic association with dsRNA, whereas the homodimeric versi on forms a stable complex with dsRNA. Based on these findings, we pro pose a two-step equilibrium model where the RNA fluctuates between do uble-stranded and melted conformations, followed by peptide binding, which results in plectonemes. Our approach can inform the design of m ore potent and effective dsRNA binders for therapeutic and diagnostic applications.
12:50 -13:45 Paul Jansen from ASML Research, Veldhoven
Title: Plasma Inter actions in EUV Lithography Machines
Abstract:& nbsp;EUV scanners operate in a low‑pressure hydrogen envir onment in which each exposure pulse generates a short‑lived EUV‑i nduced plasma. While this plasma helps mitigate carbon contamination, it simultaneously drives a range of surface, chemical, and charging phenomena that influence material durability and particulate contamin ation (defectivity).
In this colloquium, I will examine how EUV ‑induced hydrogen plasmas form and evolve, how they interact with m aterials, and how they affect particulate charging and release. I wil l show that this plasma acts as a double‑edged sword: on one hand i ts properties are deliberately exploited to keep optical surfaces cle an and to manage charge accumulation, while on the other hand it intr oduces mechanisms that complicate reliable high‑volume manufacturin g.
The aim is to provide a physics‑based perspective on how t ransient EUV‑driven plasmas shape scanner performance through their impact on materials and reticles, and why understanding these intera ctions – both in laboratory setups and in situ - is essential for robust next‑generation chip production.
DESCRIPTION: 12:30 - 12:50 Zainab Rashid, PostDoc, Physics of Living Systems, VU Amsterdam Title: TAV2b Peptide De rivatives Underwind and Stabilize Double- Stranded RNA upon Binding Abstract: Double-stranded RNA (dsRNA) has be come an essential tool to understand biological processes with promis ing therapeutic implications. However, its usage is often limited due to poor cellular uptake and instability in biological settings. Pept idic dsRNA binders, inspired by natural RNA-binding proteins, have em erged as promising tools to address these limitations. However, it re mains unclear how these peptides recognize RNA and impact its mechani cal properties. Here we employed single-molecule magnetic tweezers to investigate TAV2b-derived peptidic dsRNA binders. We showed that the se peptides underwind dsRNA upon binding and stabilize the resulting dsRNA conformation. Additionally, the wild-type peptide increases the dsRNA contour length while significantly lowering the persistence le ngth. In contrast, a high-affinity homodimeric derivative condenses t he dsRNA tether at forces below 1 pN. Furthermore, real-time experime nts performed to understand the binding mechanism of TAV2b-derived pe ptides showed that the wild-type derivative is in dynamic association with dsRNA, whereas the homodimeric version forms a stable complex w ith dsRNA. Based on these findings, we propose a two-step equilibrium model where the RNA fluctuates between double-stranded and melted co nformations, followed by peptide binding, which results in plectoneme s. Our approach can inform the design of more potent and effective ds RNA binders for therapeutic and diagnostic applications. 12:5 0 -13:45 Paul Jansen from ASML Research, Veldhoven