| 1. |
|
|
| 2. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
|
|
| 3. |
- Schifferdecker, Anna, et al.
(författare)
-
Alcohol dehydrogenase gene ADH3 activates glucose alcoholic fermentation in genetically engineered Dekkera bruxellensis yeast.
- 2016
-
Ingår i: Applied Microbiology and Biotechnology. - : Springer Science and Business Media LLC. - 1432-0614 .- 0175-7598.
-
Tidskriftsartikel (refereegranskat)abstract
- Dekkera bruxellensis is a non-conventional Crabtree-positive yeast with a good ethanol production capability. Compared to Saccharomyces cerevisiae, its tolerance to acidic pH and its utilization of alternative carbon sources make it a promising organism for producing biofuel. In this study, we developed an auxotrophic transformation system and an expression vector, which enabled the manipulation of D. bruxellensis, thereby improving its fermentative performance. Its gene ADH3, coding for alcohol dehydrogenase, was cloned and overexpressed under the control of the strong and constitutive promoter TEF1. Our recombinant D. bruxellensis strain displayed 1.4 and 1.7 times faster specific glucose consumption rate during aerobic and anaerobic glucose fermentations, respectively; it yielded 1.2 times and 1.5 times more ethanol than did the parental strain under aerobic and anaerobic conditions, respectively. The overexpression of ADH3 in D. bruxellensis also reduced the inhibition of fermentation by anaerobiosis, the "Custer effect". Thus, the fermentative capacity of D. bruxellensis could be further improved by metabolic engineering.
|
|
| 4. |
- Zhybak, Mykhailo T., et al.
(författare)
-
Amperometric L-arginine biosensor based on a novel recombinant arginine deiminase
- 2017
-
Ingår i: Microchimica Acta. - : SPRINGER WIEN. - 0026-3672 .- 1436-5073. ; 184:8, s. 2679-2686
-
Tidskriftsartikel (refereegranskat)abstract
- The authors describe an amperometric biosensor for the amino acid L-arginine (L-Arg). It is based on the use of a Nafion/Polyaniline (PANi) composite on a platinum screen-printed electrode (Pt-SPE) using a novel recombinant arginine deiminase isolated from Mycoplasma hominis. The protein was over-expressed, purified and employed as a biorecognition element of the sensor. Enzymatic hydrolysis of L-Arg leads to the formation of ammonium ions which diffuse into the Nafion/PANi layer and induce the electroreduction of PANi at a potential of -0.35 V (vs Ag/AgCl). L-Arg sensitivity is 684 +/- 32 A.M-1.m(-2), and the apparent Michaelis-Menten constant K-M(app)) is 0.31 +/- 0.05 mM. The calibration plot is linear over the range 3-200 mu M L-Arg, the limit of detection is 1 mu M, and the response time (for 90% of the total signal change to occur) is 15 s. The sensor is selective and exhibits good storage stability (amp;gt; 1 month without loss in signal). The biosensor was applied to the analysis of L-Arg in pharmaceutical samples and of ammonium and L-Arg in spiked human plasma obtained from blood of healthy volunteers and those with a hepatic disorder. Data generated were found to be in good agreement with a reference fluorometric enzymatic assay.
|
|
