•Alcalase and collagenase degraded collagen type I completely, other enzymes only to some extent.•Pretreatment by boiling for 5min improved the hydrolysis with most enzymes.•A high pressure treatment ...at 600MPa improved hydrolysis and ACE-inhibition with Alcalase and collagenase.•Alcalase hydrolysates showed the highest DH and ACE-inhibition.•New potential ACE-inhibitory peptides released by Alcalase were identified.
Bovine collagen was pre-treated (boiled or high pressure (HP)-treated) and then hydrolysed by 6 proteases. The degree of hydrolysis (DH) and the angiotensin-converting enzyme (ACE)-inhibitory activity of hydrolysates were measured. All enzymes used were able to partly degrade collagen and release ACE-inhibitory peptides. The highest ACE-inhibitory activity was obtained with Alcalase. Pretreatment significantly influenced the DH and ACE-inhibition. For most enzymes, boiling for 5min resulted in a significantly higher DH and ACE-inhibitory activity. With Alcalase and collagenase, hydrolysis and release of ACE-inhibitory peptides occurred without any pretreatment, but HP-treatment significantly improved the DH and ACE-inhibitory activity. HP did not markedly affect the hydrolysis with the other enzymes. The major peptides obtained with Alcalase were identified; all were released from the triple helix structure of collagen. Many of these peptides had C-terminal sequences similar to known ACE-inhibitory peptides. The present results suggest that collagen-rich food materials are good substrates for the release of potent ACE-inhibitory peptides, when proper pre-treatment and enzymatic treatment is applied.
•Solubility of proteins decreases considerably at pressures above 400MPa.•Aggregation results mainly from H-bonds formed during HP treatment.•Soluble proteins are structure-modified even at ...200MPa.•Modifications results in a higher fraction of loosely bound water.
Complementary methodologies were used to analyse the pressure-induced modification and functionality of myofibrillar proteins from pork meat pressurised at 200, 400, 600, or 800MPa (10min, 5 or 20°C). Pressure at 400MPa was found to be the threshold for loss of solubility, and the structural proteins, myosin and actin, lost their native solubility due to aggregation. The results from the extraction of proteins with different reagents targeting the disruption of specific molecular interactions suggested that pressure-induced aggregation was caused mainly by hydrogen bonding during pressurisation and not hydrophobic interactions nor disulphide cross-links. Furthermore, the soluble proteins were exposed to remarkable structural changes already at 200MPa and lost their native functionality. The modification of the proteins in pressurised meat affected the water binding sites of the myofibrillar proteins and, thereby, the interactions between proteins and water molecules, and distribution between myofibrillar and extra-myofibrillar compartments.
During maturation of Parma ham a continuing increase in concentration of glycerol, choline, and free amino acids, as followed for 15months by high resolution 1H NMR of ham extracts, indicates ...activity of lipolytic and proteolytic enzymes. Proteolysis was shown to be mediated by endogenous cathepsins with detectable activity even at the latest stage of maturation. The concentration of red proteinous pigments containing zinc–protoporphyrin-IX (Zn–PP), as measured by fluorescence spectroscopy, increased throughout the whole maturation period concomitant with formation of low molecular weight peptides. EPR spectroscopy showed that the concentration of the high-spin iron(III) species metmyoglobin present at early stages of production, decreased during maturation to form a EPR-silent pigment suggested to be labile, partly proteolyzed iron(II) myoglobin gradually loosing iron forming non-heme colloidal ferric hydroxide. Proteolytic degradation of myoglobin and precipitation of inorganic iron(III) in the meat matrix are essential for the metal exchange to form Zn–PP and non-heme iron(III) species.
•Mechanism of formation of red pigments in Parma ham during maturation•Zinc–protoporphyrin-IX increases throughout the Parma ham maturation period.•Proteolytic degradation of myoglobin is essential for heme transmetallation.
•Partial pepsin proteolysis of myoglobin enhances formation of zinc protoporphyrin IX.•Recombinant ferrochelatase may find practical use for color formation in meat curing.•Salt protects ...ferrochelatase against chemical and thermal denaturation.•Zinc/iron transmetallation proceed through a myoglobin-enzyme-zinc tertiary complex.
Recombinant ferrochelatase (BsFECH) from Bacillus subtilis expressed in Escherichia coli BL21(DE3) was found by UV-visible spectroscopy to bind the model substrate tetraphenylporphyrin-sulfonate, TPPS, with Ka=3.8 105mol/L in aqueous phosphate buffer pH 5.7 at 30°C, and to interact with metmyoglobin with Ka=1.07±0.13 105mol/L at 30°C. The iron/zinc exchange in myoglobin occurring during maturation of Parma hams seems to depend on such substrate binding to BsFECH and was facilitated by limited pepsin proteolysis of myoglobin to open a reaction channel for metal exchange still with BsFECH associated to globin. BsFECH increased rate of zinc insertion in TPPS significantly and showed saturation kinetics with an apparent binding constant of Zn(II) to the enzyme-TPPS complex of 1.3 104mol/L and a first-order rate constant of 6.6 10−1s−1 for dissociation of the tertiary complex, a similar pattern was found for zinc/iron transmetallation in myoglobin.
COVID-19 has resulted in widespread changes, including within the realm of sports. Professional soccer has adapted by allowing more substitutions, leading to tactical adjustments and potential ...physical benefits. Accordingly, this study analyzed the impact of the new rule in Italian top-level soccer, focusing on substitution patterns and performance differences between the pre-COVID (2017–2018, 2018–2019 seasons) and post COVID (2020–2021, 2021–2022 seasons) eras. As such, publicly available data from 1520 matches (760 matches per era) were recorded. The sample included matches played from 40 Italian top division teams in both the pre- and post-COVID eras. Analyses confirmed substitutions follow a consistent temporal pattern throughout the match in both eras, highlighting a slight difference in second-half management, and showed the new rule is still not used to its full potential, thus raising concerns about teams’ financial strength, as not all managers possess “deep benches” (i.e., a large number of top-level players available to play). Further analyses revealed a statistically significant increment (p = 0.002) in the quantity of collectively produced sprints in the post-COVID era compared to the pre-COVID one. The results from this study emphasize the need to carefully address sprint preparation and repeated sprint abilities, also considering factors such as the number of substitutes and their skill level.
Purpose
Cancer-related fatigue (CRF) is one of the most common symptoms experienced by cancer patients (CPs). The Brief Fatigue Inventory (BFI) is a reliable instrument to assess CRF in CPs. The aim ...of this study was to evaluate the psychometric properties of the Italian version of the BFI (BFI-I).
Methods
The BFI-I was developed by using the forward–backward translation approach. The psychometric properties of the BFI-I were assessed in terms of acceptability, internal consistency, and validity. Outpatient CPs filled in BFI-I along with the Medical Outcome Study Quality of Life Short Form 36 (SF36). Demographic and health data were collected.
Results
The BFI-I had an overall Cronbach alpha for the nine items of 0.94. The inter-item mean correlation was 0.64, and coefficients ranged from 0.47 to 0.81 for the nine items. The results of the factor analysis suggested a 1-factor solution explaining 68 % of the variance, supporting the hypothesis of unidimensionality of the BFI-I. The BFI-I score was compared to SF36 subscales score to evaluate concurrent validity. An expected inverse correlation between the BFI-I and the vitality subscale of the SF36 was observed (
r
= −0.67, 95 % confidence interval −0.73 to −0.59). The correlation with the other subscales of the SF36 ranged between −0.56 and −0.13. Discriminant validity analysis showed the BFI-I mean score significantly increased with increasing Eastern Cooperative Oncology Group values (
p
< 0.001).
Conclusions
BFI-I is a clinical instrument with satisfactory psychometric properties to assess CRF in Italian CPs.
Background Homozygous familial hypercholesterolemia (HoFH) is a rare, genetically determined condition of highly elevated low-density lipoprotein cholesterol (LDLC) levels. If untreated, patients do ...not typically survive beyond the second decade of life. Traditional lipid-lowering therapies (statins and ezetimibe) are largely ineffective in HoFH patients, and extracorporeal lipoprotein apheresis (LA) forms the mainstay of treatment. Lomitapide is a microsomal triglyceride transfer protein inhibitor approved for the treatment of HoFH as an adjunct to LA. We undertook to examine the efficacy and safety of lomitapide in 7 HoFH patients treated with LA in the Lipid Clinic and Therapeutic Apheresis Unit in Rome, Italy outside a clinical trial setting. Methods Seven patients with genetically determined HoFH were treated with lomitapide in the normal course of their therapy. All patients received LA either weekly or biweekly. Lomitapide was administered according to the approved European Union prescribing information. LDLC levels, liver enzymes, and hepatic fat were monitored. Length of follow-up varied between 12 and 50 weeks. Results After titration, lomitapide doses ranged from 10 to 30 mg/d for most (5/7) patients. One patient received lomitapide 60 mg/d and another 5 mg/d. Three patients achieved LDLC reductions of >50%. The patient on the lowest lomitapide dose did not gain significant benefit. Gastrointestinal adverse events (AEs) were managed via alterations to dietary fat intake. Conclusion Lomitapide is an effective adjunct to LA in patients with HoFH. AEs are manageable; gastrointestinal AEs can be managed with a low-fat eating plan.
Os tumores de pênis são de ocorrência rara, sendo responsáveis por menos de 1% das neoplasias que acometem o homem. Ainda mais infreqüente é a presença de um melanoma maligno peniano primário. ...Trata-se de uma neoplasia de prognóstico ruim e que deve ser manejada de forma radical. Relatamos um caso de melanoma maligno primário da glande peniana e fazemos breve revisão da literatura.
Riboflavin Photosensitized Oxidation of Myoglobin Grippa, Juliana M; de Zawadzki, Andressa; Grossi, Alberto B ...
Journal of agricultural and food chemistry,
02/2014, Letnik:
62, Številka:
5
Journal Article
Recenzirano
The reaction of the fresh meat pigment oxymyoglobin, MbFe(II)O2, and its oxidized form metmyoglobin, MbFe(III), with triplet-state riboflavin involves the pigment protein, which is oxidatively ...cleaved or dimerized as shown by SDS–PAGE and Western blotting. The overall rate constant for oxidation of MbFe(II)O2 by 3Rib is (3.0 ± 0.5) × 109 L·mol–1·s–1 and (3.1 ± 0.4) × 109 L·mol–1·s–1 for MbFe(III) in phosphate buffer of pH 7.4 at 25 °C as determined by laser flash photolysis. The high rates are rationalized by ground state hydrophobic interactions as detected as static quenching of fluorescence from singlet-excited state riboflavin by myoglobins using time-resolved fluorescence spectroscopy and a Stern–Volmer approach. Binding of riboflavin to MbFe(III) has K a = (1.2 ± 0.2) × 104 mol·L–1 with ΔH° = −112 ± 22 kJ·mol–1 and ΔS° = −296 ± 75 J·mol–1·K–1. For meat, riboflavin is concluded to be a photosensitizer for protein oxidation but not for discoloration.
Abstract Myogenesis is a complex sequence of events, including the irreversible transition from the proliferation-competent myoblast stage into fused, multinucleated myotubes. Myogenic ...differentiation is regulated by positive and negative signals from surrounding tissues. Stimulation due to stretch- or load-induced signaling is now beginning to be understood as a factor which affects various signal transduction pathways, gene sequences and protein synthesis. One indication of which cells are competent to undergo the fusion process is their expression of two proteins, Myo-D and myogenin. The mechanism by which the cells are able to to regulate Myo-D and myogenin is poorly understood. In the present work, we investigate the role of mechanical loading, through specific receptors to intracellular matrix proteins such as laminin and fibronectin, in both Myo-D and myogenin expression in C2 C12 cells. We propose to elucidate also the signaling pathway by which this mechanical stimulation can causes an increase in protein expression. When mechanically stimulated via laminin receptors on cell surface, C2 C12 cells showed an increase in cell proliferation and differentiation. Populations undergoing mechanical stimulation through laminin receptors show an increase in expression of Myo-D, myogenin and an increase in ERK1/2 phosphorylation. Cells stimulated via fibronectin receptors show no significant increases in fusion competence. We conclude that load induced signalling through integrin containing laminin recepotors plays a role in myoblast differentiation and fusion.
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