Chalmers University of Technology

About: Chalmers University of Technology is a education organization based out in Gothenburg, Sweden. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 17191 authors who have published 53951 publications receiving 1520592 citations. The organization is also known as: Chalmers Tekniska Högskola & Chalmers.

Plasmonic sensing characteristics of single nanometric holes.

Abstract: The optical response of isolated holes in 20 nm thin gold is probed as a function of alkanethiol CH3(CH2)(x)SH (x is an element of 1-15) and protein adsorption using dark-field spectroscopy. We establish that the plasmon excitations of single and short-range ordered 60 nm holes exhibit similar E-field decay lengths delta approximate to 10-20 nm and that a single hole can be used to resolve the successive adsorption of a protein (biotin-BSA) and its interaction partner (neutravidin). The data confirm the localized character of the hole plasmon and demonstrate that its applicability for bio/chemosensing is similar to that of particle plasmons.

High incidence of DNA mutations and gene amplifications of the ALK gene in advanced sporadic neuroblastoma tumours.

Abstract: ALK (anaplastic lymphoma kinase) is oncogenic in several tumours and has recently been identified as a predisposition gene for familial NB (neuroblastoma) harbouring mutations in the TKD (tyrosine kinase domain). We have analysed a large set of sporadic human NB primary tumours of all clinical stages for chromosomal re-arrangements using a CGH (comparative genomic hybridization) array (n=108) and mutations of the ALK gene (n=90), and expression of ALK and related genes (n=19). ALK amplification or in-gene re-arrangements were found in 5% of NB tumours and mutations were found in 11%, including two novel not previously published mutations in the TKD, c.3733T>A and c.3735C>A. DNA mutations in the TKD and gene amplifications were only found in advanced large primary tumours or metastatic tumours, and correlated with the expression levels of ALK and downstream genes as well as other unfavourable features, and poor outcome. The results of the present study support that the ALK protein contributes to NB oncogenesis providing a highly interesting putative therapeutic target in a subset of unfavourable NB tumours.

X-Ray Structure of Sensory Rhodopsin II at 2.1 A Resolution

Abstract: Sensory rhodopsins (SRs) belong to a subfamily of heptahelical transmembrane proteins containing a retinal chromophore. These photoreceptors mediate the cascade of vision in animal eyes and phototaxis in archaebacteria and unicellular flagellated algae. Signal transduction by these photoreceptors occurs by means of transducer proteins. The two archaebacterial sensory rhodopsins SRI and SRII are coupled to the membrane-bound HtrI and HtrII transducer proteins. Activation of these proteins initiates phosphorylation cascades that modulate the flagellar motors, resulting in either attractant (SRI) or repellent (SRII) phototaxis. In addition, transducer-free SRI and SRII were shown to operate as proton pumps, analogous to bacteriorhodopsin. Here, we present the x-ray structure of SRII from Natronobacterium pharaonis (pSRII) at 2.1-Å resolution, revealing a unique molecular architecture of the retinal-binding pocket. In particular, the structure of pSRII exhibits a largely unbent conformation of the retinal (as compared with bacteriorhodopsin and halorhodopsin), a hydroxyl group of Thr-204 in the vicinity of the Schiff base, and an outward orientation of the guanidinium group of Arg-72. Furthermore, the structure reveals a putative chloride ion that is coupled to the Schiff base by means of a hydrogen-bond network and a unique, positively charged surface patch for a probable interaction with HtrII. The high-resolution structure of pSRII provides a structural basis to elucidate the mechanisms of phototransduction and color tuning.