No abstract

Ras proteins are small guanine nucleotide binding proteins that regulate many cellular processes, including growth control. They undergo distinct post‐translational lipid modifications that are required for appropriate targeting to membranes. This, in turn, is critical for Ras biological function. However, most in vitro studies have been conducted on nonlipidated truncated forms of Ras proteins. Here, for the first time, attenuated total reflectance‐FTIR studies of lipid‐modified membrane‐bound N‐Ras are performed, and compared with nonlipidated truncated Ras in solution. For these studies, lipidated N‐Ras was prepared by linking a farnesylated and hexadecylated N‐Ras lipopeptide to a truncated N‐Ras protein (residues 1–181). It was then bound to a 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine bilayer tethered on an attenuated total reflectance crystal. The structurally sensitive amide I absorbance band in the IR was detected and analysed to determine the secondary structure of the protein. The NMR three‐dimensional structure of truncated Ras was used to calibrate the contributions of the different secondary structural elements to the amide I absorbance band of truncated Ras. Using this novel approach, the correct decomposition was selected from several possible solutions. The same parameter set was then used for the membrane‐bound lipidated Ras, and provided a reliable decomposition for the membrane‐bound form in comparison with truncated Ras. This comparison indicates that the secondary structure of membrane‐bound Ras is similar to that determined for the nonlipidated truncated Ras protein for the highly conserved G‐domain. This result validates the multitude of investigations of truncated Ras without anchor in vitro. The novel attenuated total reflectance approach opens the way for detailed studies of the interaction network of the membrane‐bound Ras protein.

In this report, we present a new detection method for blood glucose, using gold nanorod SERS; a surface enhanced Raman scattering probe embedded in two component self-assembled monolayers (SAMs).

No abstract

The burden of health-care related services in a global era with continuously increasing population and inefficient dissipation of the resources requires effective solutions. From this perspective, point-of-care diagnostics is a demanded field in clinics. It is also necessary both for prompt diagnosis and for providing health services evenly throughout the population, including the rural districts. The requirements can only be fulfilled by technologies whose productivity has already been proven, such as complementary metal-oxide-semiconductors (CMOS). CMOS-based products can enable clinical tests in a fast, simple, safe, and reliable manner, with improved sensitivities. Portability due to diminished sensor dimensions and compactness of the test set-ups, along with low sample and power consumption, is another vital feature. CMOS-based sensors for cell studies have the potential to become essential counterparts of point-of-care diagnostics technologies. Hence, this review attempts to inform on the sensors fabricated with CMOS technology for point-of-care diagnostic studies, with a focus on CMOS image sensors and capacitance sensors for cell studies.