Molecular Properties of Human Guanylate Cyclase-Activating Protein 3 (GCAP3) and Its Possible Association with Retinitis Pigmentosa

The cone-specific guanylate cyclase-activating protein 3 (GCAP3), encoded by the GUCA1C gene, has been shown to regulate the enzymatic activity of membrane-bound guanylate cyclases (GCs) in bovine and teleost fish photoreceptors, to an extent comparable to that of the paralog protein GCAP1. To date, the molecular mechanisms underlying GCAP3 function remain largely unexplored. In this work, we report a thorough characterization of the biochemical and biophysical properties of human GCAP3, moreover, we identified an isolated case of retinitis pigmentosa, in which a patient carried the c.301G > C mutation in GUCA1C, resulting in the substitution of a highly conserved aspartate residue by a histidine (p.(D101H)). We found that myristoylated GCAP3 can activate GC1 with a similar Ca²⁺-dependent profile, but significantly less efficiently than GCAP1. The non-myristoylated form did not induce appreciable regulation of GC1, nor did the p.D101H variant. GCAP3 forms dimers under physiological conditions, but at odds with its paralogs, it tends to form temperature-dependent aggregates driven by hydrophobic interactions. The peculiar properties of GCAP3 were confirmed by 2 µs molecular dynamics simulations, which for the p.D101H variant highlighted a very high structural flexibility and a clear tendency to lose the binding of a Ca²⁺ ion to EF3. Overall, our data show that GCAP3 has unusual biochemical properties, which make the protein significantly different from GCAP1 and GCAP2. Moreover, the newly identified point mutation resulting in a substantially unfunctional protein could trigger retinitis pigmentosa through a currently unknown mechanism.     

Objective evaluation of multidirectional fabric creasing

Creasing is one of the most important properties of textiles for apparel application. Most fabrics are regularly evaluated by means of etalons, that is, visual standards. Nevertheless, due to the disadvantages of visual evaluation, which is unreliable and time consuming, several objective methods were developed. In this article, a new objective method of multidirectional evaluation of creasing is described. We have proposed the test method of angle recovery using image processing. The specimen of the fabric was of a circular shape and it was measured by the method of angle recovery in various directions. We compared the results obtained from our method with the method described by Sommer and by the hollow cylinder method also. We found good conformity between the results obtained from our method and the method described by Sommer.     

The characterisation of lactic acid bacteria during the fermentation of an artisan Serbian sausage (Petrovská Klobása)

Petrovská Klobása is an artisan Serbian sausage made only from meat and spices without any additives or starter cultures. In order to characterise lactic acid bacteria (LAB) microflora, a total number of 404 LAB strains were isolated from 15 samples collected during 90 days of the fermentation and 120 days of storage of one batch of Petrovská Klobása. The isolates were preliminarily identified by phenotypic tests and subjected to (GTG)₅-PCR fingerprinting. Representatives of each group were identified by 16S rDNA sequencing. The results showed that among the isolates, Lactobacillus sakei and Leuconostoc mesenteroides predominate with 36.4% and 37.1% of total LAB strains, respectively. Pediococcus pentosaceus was also isolated in high proportion (18.4%) whereas Enterococcus durans and Enterococcus caseliflavus made only 1% and 6% of the total isolates, correspondingly. The analysis of vacuum packed and modified atmosphere packed (MAP) samples showed higher presence of L. mesenteroides and L. sakei in the total microflora.     

The Publication Productivity of Young Scientists: An Empirical Study

This research was conducted on a sample of 840 respondents who represent half of the Croatian population of young scientists. There are three main features which define the publication productivity of young scientists. 1) Despite the worsened position of R & D, they publish more scientific papers than the young generations of scientists at the beginning of the nineties. 2) Differences between a highly-productive minority, which produces on average half of all scientific publications, and a low-productive majority is already apparent in young scientists. 3) The productivity of young scientists is formed according to productivity patterns typical of particular scientific fields and disciplines.With regard to the explanation of productivity, the following has been found. a) An expansion of the set of predictors resulted in an improvement in the explanation of the productivity of young scientists compared with previous surveys. b) Among the factors which contribute significantly to the explanation of the quantity of scientific publications, the most powerful predictor is attendance at conferences abroad, followed by scientific qualifications and some gatekeeping variables. c) Besides certain similarities, scientific fields also show a specific structure of determinants of young scientists' productivity.     

The study of chlorination kinetics of copper(I)sulfide by calcium chloride in the presence of oxygen

The article investigates the influence of temperature, time, quantity of calcium chloride, and oxygen flow on the chlorination degree of copper(I)sulfide by calcium chloride in the presence of oxygen. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis were used to determine morphological changes occurring with the change of temperature and time. The law of additive time and the method of stationary point were used to determine kinetic parameters, i.e., rate constant and activation energy.     

Mechanical and thermal properties of UV cured mixtures of linear and hyperbranched urethane acrylates

The properties of urethane acrylate resin mixtures based on the linear and hyperbranched aliphatic polyesters were examined. Linear polyester was synthesized from neopentil glycol and adipic acid. Hyperbranched polyester of the third generation was synthesized from 2,2-bis(hydroxymethyl)propionic acid and di-trimethylol propane. The modification of 60% of hyperbranched aliphatic polyester OH end groups was carried out with isononanoic acid or with soybean fatty acids. Two hyperbranched urethane acrylates, with the same degree of acrylation, and one linear urethane acrylate were obtained by reaction of appropriate polyester and isophorone diisocyanate and 2-hydroxyethyl acrylate. The influence of added amount of HUA and nature of non-acrylic end groups on the rheological, mechanical and thermal properties of the uncured and UV cured mixtures diluted with 20 wt.% hexanediol diacrylate was examined. The nature of non-acrylic end groups have great effect on the interaction between linear and hyperbranched urethane acrylates, which further has a crucial influence on the examined properties of uncured and UV cured mixture samples.     

Immobilization of laccase from Myceliophthora thermophila on functionalized silica nanoparticles: Optimization and application in lindane degradation

This work is focused on immobilization of laccase from Myceliophthora thermophila expressed in Aspergillus oryzae(Novozym 51003? laccase) on amino modified fumed nano-silica(AFNS) and the possible use in bioremediation. Hereby, for the first time, factors affecting the immobilization of Novozym 51003? laccase on AFNS were investigated for defining the immobilization mechanism and optimizing the utilization of AFNS as support for laccase immobilization. The highest specific activity(13.1 IU·mg~(-1) proteins) was achieved at offered 160 mg per g of AFNS and for the same offered protein concentration the highest activity immobilization yield, reaching68.3% after the equilibrium time, at optimum pH 5.0, was obtained. Laccase immobilization occurs by adsorption as monolayer enzyme binding in 40 min, following pseudo-first-order kinetics. The possible use of obtained immobilized preparation was investigated in degradation of pesticide lindane. Within 24 h, lindane concentration was reduced to 56.8% of initial concentration and after seven repeated reuses it retained 70% of the original activity.