Jens Struckmeier

Imaging and detecting molecular interactions of single transmembrane proteins.

Single-molecule atomic force microscopy (AFM) provides novel ways to characterize structure-function relationships of native membrane proteins. High-resolution AFM-topographs allow observing substructures of single membrane proteins at sub-nanometer resolution as well as their conformational changes, oligomeric state, molecular dynamics and assembly. Complementary to AFM imaging, single-molecule force spectroscopy experiments allow detecting molecular interactions established within and between membrane proteins. The sensitivity of this method makes it possible to detect the interactions that stabilize secondary structures such as transmembrane alpha-helices, polypeptide loops and segments within. Changes in temperature or protein-protein assembly do not change the position of stable structural segments, but influence their stability established by collective molecular interactions. Such changes alter the probability of proteins to choose a certain unfolding pathway. Recent examples have elucidated unfolding and refolding pathways of membrane proteins as well as their energy landscapes. We review current and future potential of these approaches to reveal insights into membrane protein structure, function, and unfolding as we recognize that they could help answering key questions in the molecular basis of certain neuro-pathological dysfunctions.

Energy minimization at all layers of the data center: The ParaDIME project

The main objective of the ParaDIME project has been to minimize energy consumption at all levels of the data center. On the one hand, we have considered what can be achieved on currently existing systems, via improvements of the programming model and the runtime system. On the other hand, we investigated which techniques and design decisions can make future computing nodes more energy efficient. We have successfully proposed and developed several methodologies that enable up to 60% energy savings in data centers components.