Mini-Intein Structures from Extremophiles Suggest a Strategy for Finding Novel Robust Inteins

Inteins are prevalent among extremophiles. Mini-inteins with robust splicing properties are of particular interest for biotechnological applications due to their small size. However, biochemical and structural characterization has still been limited to a small number of inteins, and only a few serve as widely used tools in protein engineering. We determined the crystal structure of a naturally occurring Pol-II mini-intein from Pyrococcus horikoshii and compared all three mini-inteins found in the genome of P. horikoshii. Despite their similar sizes, the comparison revealed distinct differences in the insertions and deletions, implying specific evolutionary pathways from distinct ancestral origins. Our studies suggest that sporadically distributed mini-inteins might be more promising for further protein engineering applications than highly conserved mini-inteins. Structural investigations of additional inteins could guide the shortest path to finding novel robust mini-inteins suitable for various protein engineering purposes

Drift compensation using a multichannel slot waveguide Young interferometer

Polymeric integrated Young interferometer sensor chips utilizing a slot waveguide have demonstrated to be sensitive, to work at visible wavelengths, to be manufacturable by simple process, and to have a reduced sensitivity to temperature fluctuations. Although slot waveguide Young interferometers have these desirable features for low-cost rapid diagnostics, the sensor readout is disturbed by mechanical drifts of the sensing system. In this paper we demonstrate that mechanical drifts of the readout system can be compensated by using a multichannel slot waveguide Young interferometer having two reference waveguides and applying a drift compensation method based on the analysis of the spatial shifts of the interferogram fringes. The applicability of the drift compensation method was studied by conducting experiments with undisturbed and with mechanically disturbed setup to measure the phase changes induced by the changes of the bulk refractive index. By applying the drift compensation method, the sample induced phase change responses were extracted from up to 18 times larger measured phase changes in the disturbed experiments proving the applicability of the method with multichannel slot waveguide Young interferometers

Exploration of Microbial Communities Using the Thermo Scientific Varioskan LUX Multimode Reader and the Invitrogen EVOS FL Cell Imaging System

Non peer reviewe

Structural studies on Δ3-Δ2-enoyl-CoA isomerase: the variable mode of assembly of the trimeric disks of the crotonase superfamily

AbstractSubunits of the enzymes in the crotonase superfamily form tight trimeric disks. In most members of this protein superfamily these disks assemble further into hexamers. Here we report on the 2.1 Å structure of a tight hexameric crystal form of the yeast peroxisomal Δ3-Δ2-enoyl-CoA isomerase (Eci1p). A comparison of this structure to a previously solved crystal form of Eci1p and other structures of this superfamily shows that there is much variability with respect to the relative distance between the disks and their relative orientations. In particular helices H2 and H9 are involved in the inter-trimer contacts and there are considerable structural differences in these helices in this superfamily. Helices H2 and H9 are near the catalytic cavity and it is postulated that the observed structural variability of these helices, stabilized by the different modes of assembly, has allowed the evolution of the wide range of substrate and catalytic specificity within this enzyme superfamily

Tulkkien työmuistista ja toiminnanohjauksesta

Peer reviewe

Analysis of ground heat exchanger for a ground source heat pump : A study of an existing system to find optimal borehole length to enhance the coefficient of performance

Ground Source Heat Hump is one of the emerging technic to utilize the reservoir of geothermal energy in Europe. The crucial factor is to find the optimal length of the borehole to successfully design a heating system. The length of the borehole varies depending on the geographical area, the capacity of the heat pump and heat load of the desired building in consideration. Several methods have been theorized and validated using the experimental measurements to find the optimal length of the borehole. The most commonly used methods are American Society of Heating, Refrigeration and Air-conditioning Engineers and International Ground Source Heat Pump Association for sizing borehole heat exchanger. In this paper, an existing system is analyzed, for a 60 kilo Watts heat pump in an area of Finland with a ground source 250 meters of Borehole Heat Exchanger. Coefficient of Performance for current scenario is calculated, an optimal length is found for the heat capacity of the heat pump to enhance the performance of the system. Improved coefficient of performance is presented along with an easy method of finding the optimal length of the ground source.fi=vertaisarvioitu|en=peerReviewed

Effects of four different antihypertensive drugs on plasma metabolomic profiles in patients with essential hypertension

Objective In order to search for metabolic biomarkers of antihypertensive drug responsiveness, we measured > 600 biochemicals in plasma samples of subjects participating in the GENRES Study. Hypertensive men received in a double-blind rotational fashion amlodipine, bisoprolol, hydrochlorothiazide and losartan, each as a monotherapy for one month, with intervening one-month placebo cycles. Methods Metabolomic analysis was carried out using ultra high performance liquid chromatography-tandem mass spectrometry. Full metabolomic signatures (the drug cycles and the mean of the 3 placebo cycles) became available in 38 to 42 patients for each drug. Blood pressure was monitored by 24-h recordings. Results Amlodipine (P values down to 0.002), bisoprolol (P values down to 2 x 10(-5)) and losartan (P values down to 2 x 10(-4)) consistently decreased the circulating levels of long-chain acylcarnitines. Bisoprolol tended to decrease (P values down to 0.002) the levels of several medium-and long-chain fatty acids. Hydrochlorothiazide administration was associated with an increase of plasma uric acid level (P = 5 x 10(-4)) and urea cycle metabolites. Decreases of both systolic (P = 0.06) and diastolic (P = 0.04) blood pressure after amlodipine administration tended to associate with a decrease of plasma hexadecanedioate, a dicarboxylic fatty acid recently linked to blood pressure regulation. Conclusions Although this systematic metabolomics study failed to identify circulating metabolites convincingly predicting favorable antihypertensive response to four different drug classes, it provided accumulating evidence linking fatty acid metabolism to human hypertension.Peer reviewe