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Follicular fluid is a potent mediator of sperm acrosome reaction (AR) in vitro. The aim of this study was to investigate whether individual follicular fluids vary quantitatively in their ability to stimulate an AR, and whether such variability relates to fertilizability of the corresponding egg, its maturational level and/or progesterone content. Individual follicular fluids were obtained from 24 women undergoing in-vitro fertilization and assayed for their ability to induce an AR in normal human spermatozoa. After incubation in capacitation medium for 18 h, spermatozoa were challenged with the individual follicular fluids for 30 min. AR was detected by immunofluorescence, using fluorescein-labelled Pisum sativum lectin. We found that individual follicular fluids varied markedly in their ability to induce AR. Acrosome reaction correlated linearly with progesterone concentration (Spearman's r = 0.735, P = 0.01) at constant protein level, but no correlation was found between AR and protein concentration at constant progesterone level. Progesterone concentrations were not only higher (ANOVA, P = 0.002) in fluids from mature oocytes compared to those from less mature or post-mature eggs but also in fluids from fertilized compared to unfertilized eggs (ANOVA, P = 0.015, n = 13 patients with both fertilized and unfertilized eggs). In contrast, AR-inducing ability of individual follicular fluids did not differ for fertilized and unfertilized eggs. While AR-inducing ability appeared to increase with maturational stage of the egg, this trend was not statistically significant, probably due to small sample size. Our data suggest that progesterone rather than protein is the principal mediator of acrosome reaction induced by follicular fluid in vitro.(ABSTRACT TRUNCATED AT 250 WORDS) [ABSTRACT FROM AUTHOR]

Selenium (Se) and glutathione peroxidase (GSH-Px) were determined from the seminal plasma samples and spermatozoa of human and four different animal species. The human sperm Se concentration was 1.8±0.8 μg/g dry weight, which was about half of that in the bull. Abnormal sperm morphology and motility correlated with low sperm Se content. The volume of sperm mitochondrial sheath in human, bull and stallion was measured using transmission electron microscopy. In these species the sperm Se content was highly correlated with the volume of mitochondria. Among the five species studied, the seminal plasma level of Se was lowest in human male and stallion, while the highest levels were encountered in the bull. No correlation was obtained between human semen quality and seminal plasma Se concentration. The seminal plasma GSH-Px activity was low in man and ram, absent in boar and stallion but very high in the bull. The amount of structural sperm Se as well as seminal plasma Se and GSH-Px activity appears to be highly variable in different species [ABSTRACT FROM PUBLISHER]

The concentrations of lead, magnesium, selenium and zinc in seminal fluid from men with variable semen quality (sperm morphology, density and motility) and fertility were determined by atomic absorption spectrometer without or with Zeeman background correction. The mean (±SD) concentration of selenium in the samples ( = 142) was 28.8 ± 9.5 μg/l, which was about a third of the corresponding serum value (77.8 ± 13.3 μg/l, = 140). The serum selenium level was significantly ( < 0.001) higher in infertile than in fertile men, but the seminal fluid did not show such a difference. No correlation was obtained between selenium values in seminal plasma and sperm density or motility. The levels of lead in seminal fluid were very low with no correlation to the levels of magnesium, selenium and zinc or the semen qualities. The seminal fluid lead concentration was significantly ( < 0.001) higher in infertile (3.6 ± 3.2 μg/l, = 79) than in fertile men (1.7 ± 1.0 μg/l, = 39). Magnesium (103.5 ± 49.2 mg/l, = 90) and zinc (141.1 + 71.7 mg/l, = 157) concentrations in seminal fluid were comparable with previous reports. Both minerals showed a positive correlation to the seminal fluid selenium, while only zinc displayed a borderline correlation with sperm density. The present findings indicate that the determination of seminal fluid selenium may not offer any advantages over zinc and magnesium measurement in the fertility assessment and its role in human semen remains obscure. The low lead concentrations in the present material is a clear indication of low industrial exposure. [ABSTRACT FROM PUBLISHER]

The concentrations of selenium in the reproductive organs, seminal fluid and serum of human males and bulls were analysed using an atomic absorption spectrometer with Zeeman background correction. The mean (±SD) concentration of selenium in human seminal fluid (33.4±14.1 μg/1, = 70) was less than half the level detected in serum (78.2±9.9 μg/l, =32). In bulls, the mean selenium concentration in seminal fluid (457.4±108.7μg/1, =113) was about nine times higher than in human males, while the level in serum (49.1±5.1 μg/1, =94) was significantly (<0.001) lower than in human serum. The selenium concentration (500±244 μg/I) in the bovine seminal vesicle secretions were comparable to those in the seminal fluid and this gland appears to be mainly responsible for the high selenium levels in the seminal fluid. The mean selenium concentration in reproductive tissues of both species was highest in the testes. The distribution of selenium in the bovine epididymis was biphask. The testkular and epididymal selenium are associated mainly with macromolecules of the spermatogenk cells and spermatozoa. It was concluded that studies in farm and laboratory animals do not necessarily form a reliable basis for conclusions with regard to human male reproduction, since selenium may have a different role and importance in the reproduction of various species. [ABSTRACT FROM PUBLISHER]

In the methylotrophic yeast Komagataella phaffii, we identified an endoplasmic reticulum-resident protein disulfide isomerase (PDI) family member, Erp41, with a peculiar combination of active site motifs. Like fungal ERp38, it has two thioredoxin-like domains which contain active site motifs (a and a'), followed by an alpha-helical ERp29c C-terminal domain (c domain). However, while the a domain has a typical PDI-like active site motif (CGHC), the a' domain instead has CGYC, a glutaredoxin-like motif which confers to the protein an exceptional affinity for GSH/GSSG. This combination of active site motifs has so far been unreported in PDI-family members. Homology searches revealed ERp41 is present in the genome of some plants, fungal parasites, and a few nonconventional yeasts, among which are Komagataella spp. and Yarrowia lipolytica. These yeasts are both used for the production of secreted recombinant proteins. Here, we analyzed the activity of K. phaffii Erp41. We report that it is nonessential in K. phaffii, and that it can catalyze disulfide bond formation in partnership with the sulfhydryl oxidase Ero1 in vitro with higher turnover rates than the canonical PDI from K. phaffii, Pdi1, but slower activation times. We show how Erp41 has unusually fast glutathione-coupled oxidation activity and relate it to its unusual combination of active sites in its thioredoxin-like domains. We further describe how this determines its unusually efficient catalysis of dithiol oxidation in peptide and protein substrates., Competing Interests: Conflict of interests A patent for the CyDisCo plasmid system is held by the University of Oulu: method for producing natively folded proteins in a prokaryotic host (Patent number 9238817; date of patent January 19th, 2016). Inventor: L. W. R. The other authors declare that they have no conflict of interests with the contents of this article., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Oxidative protein folding in the endoplasmic reticulum (ER) is driven mainly by protein disulfide isomerase PDI and oxidoreductin Ero1. Their activity is tightly regulated and interconnected with the unfolded protein response (UPR). The mechanisms of disulfide bond formation have mainly been studied in human or in the yeast Saccharomyces cerevisiae. Here we analyze the kinetics of disulfide bond formation in the non-conventional yeast Komagataella phaffii, a common host for the production of recombinant secretory proteins. Surprisingly, we found significant differences with both the human and S. cerevisiae systems. Specifically, we report an inactive disulfide linked complex formed by K. phaffii Ero1 and Pdi1, similarly to the human orthologs, but not described in yeast before. Furthermore, we show how the interaction between K. phaffii Pdi1 and Ero1 is unaffected by the introduction of unfolded substrate into the system. This is drastically opposed to the previously observed behavior of the human pathway, suggesting a different regulation of the UPR and/or possibly different interaction mechanics between K. phaffii Pdi1 and Ero1., (© 2023. Springer Nature Limited.)

We report on the lifetime measurement of the 6   1 Σ g + ( 7,31 ) state of Na 2 molecules, produced in a heat-pipe oven, using a time-resolved spectroscopic technique. The 6   1 Σ g + ( 7,31 ) level was populated by two-step two-color double resonance excitation via the intermediate A   1 Σ u + ( 8,30 ) state. The excitation scheme was done using two synchronized pulsed dye lasers pumped by a Nd:YAG laser operating at the second harmonics. The fluorescence emitted upon decay to the final state was measured using a time-correlated photon counting technique, as a function of argon pressure. From this, the radiative lifetime was extracted by extrapolating the plot to collision-free zero pressure. We also report the calculated radiative lifetimes of the N a 2   6   1 Σ g + ro-vibrational levels in the range of v = 0-200 with J = 1 and J = 31 using the LEVEL program for bound-bound and the BCONT program for bound-free transitions. Our calculations reveal the importance of the bound-free transitions on the lifetime calculations and a large difference of about a factor of three between the J = 1 and J = 31 for the v = 40 and v = 100, respectively, due to the wavefunction alternating between having predominantly inner and outer well amplitude.

Coronary artery disease is the most common cause of death globally and is linked to a number of risk factors including serum low density lipoprotein, high density lipoprotein, triglycerides and lipoprotein(a). Recently two proteins, angiopoietin-like protein 3 and 4, have emerged from genetic studies as being factors that significantly modulate plasma triglyceride levels and coronary artery disease. The exact function and mechanism of action of both proteins remains to be elucidated, however, mutations in these proteins results in up to 34% reduction in coronary artery disease and inhibition of function results in reduced plasma triglyceride levels. Here we report the crystal structures of the fibrinogen-like domains of both proteins. These structures offer new insights into the reported loss of function mutations, the mechanisms of action of the proteins and open up the possibility for the rational design of low molecular weight inhibitors for intervention in coronary artery disease.

Novel health monitoring devices and applications allow consumers easy and ubiquitous ways to monitor their health status. However, technologies from different providers lack both technical and semantic interoperability and hence the resulting health data are often deeply tied to a specific service, which is limiting its reusability and utilization in different services. We have designed a Wellness Warehouse Engine (W2E) that bridges this gap and enables seamless exchange of data between different services. W2E provides interfaces to various data sources and makes data available via unified representational state transfer application programming interface to other services. Importantly, it includes Unifier--an engine that allows transforming input data into generic units reusable by other services, and Analyzer--an engine that allows advanced analysis of input data, such as combining different data sources into new output parameters. In this paper, we describe the architecture of W2E and demonstrate its applicability by using it for unifying data from four consumer activity trackers, using a test base of 20 subjects each carrying out three different tracking sessions. Finally, we discuss challenges of building a scalable Unifier engine for the ever-enlarging number of new devices.

High levels of selenium and glutathione peroxidase (GSH-Px) were found in bull seminal plasma but low concentrations in human seminal plasma. In man the seminal plasma selenium was associated with two macromolecules separable by gel filtration, but no GSH-Px was found in the same fractions. Selenium in bull seminal plasma was associated with two proteins, which could be separated by gel filtration and anion exchange chromatography. Both macromolecules coeluted with GSH-Px activity and had identical optima at pH 7.0. Their responses to thermal treatment, however, differed. Seminal vesicle secretory fluid in the bull contained both these proteins, while the larger molecule was also found in fractionations of ampulla, prostate and Cowper's glands. The larger enzyme form is evidently a tetramer of the smaller one. Both enzyme forms were extremely sensitive to heavy metals and some divalent metal ions. GSH caused an activation while other reducing agents were suppressive. Triton X-100 had no effect, while sodium deoxycholate was inhibitory. These properties are typical for a phospholipid hydroperoxide GSH-Px. It is concluded that this selenium-dependent enzyme may be important in the protection of bovine spermatozoa against damage caused by oxygen radicals, while in man such a mechanism is not functional.