Tuning sterol extraction kinetics yields a renal-sparing polyene antifungal.

Decades of previous efforts to develop renal-sparing polyene antifungals were misguided by the classic membrane permeabilization model1. Recently, the clinically vital but also highly renal-toxic small-molecule natural product amphotericin B was instead found to kill fungi primarily by forming extramembraneous sponge-like aggregates that extract ergosterol from lipid bilayers2-6. Here we show that rapid and selective extraction of fungal ergosterol can yield potent and renal-sparing polyene antifungals. Cholesterol extraction was found to drive the toxicity of amphotericin B to human renal cells. Our examination of high-resolution structures of amphotericin B sponges in sterol-free and sterol-bound states guided us to a promising structural derivative that does not bind cholesterol and is thus renal sparing. This derivative was also less potent because it extracts ergosterol more slowly. Selective acceleration of ergosterol extraction with a second structural modification yielded a new polyene, AM-2-19, that is renal sparing in mice and primary human renal cells, potent against hundreds of pathogenic fungal strains, resistance evasive following serial passage in vitro and highly efficacious in animal models of invasive fungal infections. Thus, rational tuning of the dynamics of interactions between small molecules may lead to better treatments for fungal infections that still kill millions of people annually7,8 and potentially other resistance-evasive antimicrobials, including those that have recently been shown to operate through supramolecular structures that target specific lipids9.

Glioblastoma Multiforme: The Latest Diagnostics and Treatment Techniques.

BACKGROUND: Glioblastoma multiforme (GBM) is a WHO grade 4 glioma and the most common malignant primary brain tumour. Recently, there has been outstanding progress in the treatment of GBM. In addition to the newest form of GBM removal using fluorescence, three-dimensional (3D) imaging, tomoradiotherapy, moderate electro-hyperthermia, and adjuvant temozolomide (post-operative chemotherapy), new developments have been made in the fields of immunology, molecular biology, and virotherapy. An unusual and modern treatment has been created, especially for stage 4 GBM, using the latest therapeutic techniques, including immunotherapy and virotherapy. Modern oncological medicine is producing extraordinary and progressive therapeutic methods. Oncological therapy includes individual analysis of the properties of a tumour and targeted therapy using small-molecule inhibitors. Individualised medicine covers the entire patient (tumour and host) in the context of immunotherapy. An example is individualised multimodal immunotherapy (IMI), which relies on individual immunological tumour-host interactions. In addition, IMI is based on the concept of oncolytic virus-induced immunogenic tumour cell death. SUMMARY: In this review, we outline current knowledge of the various available treatment options used in the therapy of GBM including both traditional therapeutic strategy and modern therapies, such as tomotherapy, electro-hyperthermia, and oncolytic virotherapy, which are promising treatment strategies with the potential to improve prognosis in patients with GBM. KEY MESSAGES: This newest therapy, immunotherapy combined with virotherapy (oncolytic viruses and cancer vaccines), is displaying encouraging signs for combating GBM. Additionally, the latest 3D imaging is compared to conventional two-dimensional imaging.

Analysis of long-term outcomes in 44 patients following pelvic exenteration due to cervical cancer.

BACKGROUND: Pelvic exenteration (PE) may be associated with prolonged overall survival (OS) in selected patients with advanced or recurrent cervical cancer. However, the factors related to improved survival following PE are not clearly defined. The aim of this study was to perform a retrospective analysis of OS rates in a group of patients undergoing PE in order to identify the factors related to improved long-term outcomes. METHODS: Our study group consisted of 44 patients, including 21 squamous cell cancer (SCC) patients, 22 patients with adenocarcinomas (AC) of the cervix, and one patient with undifferentiated cervical carcinoma. The patients were categorized according to the type of surgery, namely, primary surgery (12 patients) or surgery due to cancer recurrence (32 patients). RESULTS: In the group of patients with recurrent cervical cancer, we found that improved OS correlated with the SCC histological type and the presence of vaginal fistula. The need for reoperation within 30 days and the presence of severe adverse events significantly worsened the prognosis. We found a non significant trend toward improved survival in those patients with tumor-free margins. Lymph node metastases, the initial stage of the disease, the time to recurrence, and a history of hysterectomy had no impact on patients' OS. In the group of patients undergoing primary PE, we observed a trend toward improved survival among those diagnosed with vaginal fistula. CONCLUSIONS: Pelvic exenteration seemed to improve the long-term outcomes for patients with SCC cancer recurrence and vaginal fistula whose surgery was unrelated to severe adverse events.

An Analysis of Long-Term Outcomes in Patients Treated by Extensive Bowel Resection Due to Advanced Ovarian Cancer Relative to the Effectiveness of Surgery.

INTRODUCTION: Surgery for advanced ovarian cancer (AOC) often requires bowel resections. However, the impact of bowel surgery on patient overall survival (OS) has not yet been precisely determined. OBJECTIVE: The aim of the study was to analyze the OS rates in a group of AOC patients undergoing bowel resection. METHODS: We carried out a retrospective analysis of patients who had undergone low anterior resection of the rectum (LAR) during primary or interval debulking surgery for AOC. We divided the patients into 2 groups: Group 1 included 69 patients who underwent only LAR; Group 2 included 66 patients who underwent LAR and additional bowel resection. The control group included 71 AOC patients who did not required bowel resection. RESULTS: In the subgroup of patients with no gross residual disease (NGR), there were no differences in OS between Groups 1 and 2. In the subgroup of "optimally" (tumors <1 cm) debulked patients, Group 1 patients had a higher median OS than Group 2 patients. Additionally, there was no difference between Groups 1 and 2 as far as the number of severe adverse events. CONCLUSIONS: Multiple bowel resections seem to improve OS in patients when NGR is achieved but should be avoided when complete resection is not possible.

The association between lymph node metastases and long-term survival in patients with epithelial ovarian cancer.

INTRODUCTION: A key survival prognosis factor for patients treated for ovarian cancer is complete cytoreductive surgery where all macroscopic neoplastic implants, including enlarged metastatic lymph nodes, are removed. We presume that investigating the involvement of the lymphatic system can result in a more individualized approach to the treatment of ovarian cancer patients. The main aim of our study was to analyze the relationship between the presence, number and types of lymph node metastases and ovarian cancer patient prognosis. MATERIAL AND METHODS: We carried out a retrospective analysis of patients who underwent cytoreduction due to primary ovarian cancer, between 2010 and 2015. We analyzed the number of metastatic lymph nodes, the lymph node ratio defined as the ratio of the number of metastatic lymph nodes to the total number of lymph nodes removed, extracapsular involvement, and the histopathological pattern of metastases. RESULTS: The study group included 651 patients. Of these, 377 had lymphadenectomy, 144 presented with lymph node metastases, and 233 had no lymph node metastases. We also included a group of 274 patients who did not have lymphadenectomy. Patients with more than 4 metastatic lymph nodes and a lymph node ratio of ≥ 0.1 had significantly poorer overall survival. Extracapsular involvement had no relation to patient overall survival. Multivariant survival analysis indicated that a lymph node ratio of ≥ 0.1 was an independent predictor of poor survival. CONCLUSIONS: The analysis of lymph node metastases in ovarian cancer patients can have predictive value for patient overall survival.

Loss of Miro1-directed mitochondrial movement results in a novel murine model for neuron disease.

Defective mitochondrial distribution in neurons is proposed to cause ATP depletion and calcium-buffering deficiencies that compromise cell function. However, it is unclear whether aberrant mitochondrial motility and distribution alone are sufficient to cause neurological disease. Calcium-binding mitochondrial Rho (Miro) GTPases attach mitochondria to motor proteins for anterograde and retrograde transport in neurons. Using two new KO mouse models, we demonstrate that Miro1 is essential for development of cranial motor nuclei required for respiratory control and maintenance of upper motor neurons required for ambulation. Neuron-specific loss of Miro1 causes depletion of mitochondria from corticospinal tract axons and progressive neurological deficits mirroring human upper motor neuron disease. Although Miro1-deficient neurons exhibit defects in retrograde axonal mitochondrial transport, mitochondrial respiratory function continues. Moreover, Miro1 is not essential for calcium-mediated inhibition of mitochondrial movement or mitochondrial calcium buffering. Our findings indicate that defects in mitochondrial motility and distribution are sufficient to cause neurological disease.

A Maximum-Likelihood Approach to Force-Field Calibration.

A new approach to the calibration of the force fields is proposed, in which the force-field parameters are obtained by maximum-likelihood fitting of the calculated conformational ensembles to the experimental ensembles of training system(s). The maximum-likelihood function is composed of logarithms of the Boltzmann probabilities of the experimental conformations, calculated with the current energy function. Because the theoretical distribution is given in the form of the simulated conformations only, the contributions from all of the simulated conformations, with Gaussian weights in the distances from a given experimental conformation, are added to give the contribution to the target function from this conformation. In contrast to earlier methods for force-field calibration, the approach does not suffer from the arbitrariness of dividing the decoy set into native-like and non-native structures; however, if such a division is made instead of using Gaussian weights, application of the maximum-likelihood method results in the well-known energy-gap maximization. The computational procedure consists of cycles of decoy generation and maximum-likelihood-function optimization, which are iterated until convergence is reached. The method was tested with Gaussian distributions and then applied to the physics-based coarse-grained UNRES force field for proteins. The NMR structures of the tryptophan cage, a small α-helical protein, determined at three temperatures (T = 280, 305, and 313 K) by Halabis et al. ( J. Phys. Chem. B 2012 , 116 , 6898 - 6907 ), were used. Multiplexed replica-exchange molecular dynamics was used to generate the decoys. The iterative procedure exhibited steady convergence. Three variants of optimization were tried: optimization of the energy-term weights alone and use of the experimental ensemble of the folded protein only at T = 280 K (run 1); optimization of the energy-term weights and use of experimental ensembles at all three temperatures (run 2); and optimization of the energy-term weights and the coefficients of the torsional and multibody energy terms and use of experimental ensembles at all three temperatures (run 3). The force fields were subsequently tested with a set of 14 α-helical and two α + ß proteins. Optimization run 1 resulted in better agreement with the experimental ensemble at T = 280 K compared with optimization run 2 and in comparable performance on the test set but poorer agreement of the calculated folding temperature with the experimental folding temperature. Optimization run 3 resulted in the best fit of the calculated ensembles to the experimental ones for the tryptophan cage but in much poorer performance on the training set, suggesting that use of a small α-helical protein for extensive force-field calibration resulted in overfitting of the data for this protein at the expense of transferability. The optimized force field resulting from run 2 was found to fold 13 of the 14 tested α-helical proteins and one small α + ß protein with the correct topologies; the average structures of 10 of them were predicted with accuracies of about 5 Å C(α) root-mean-square deviation or better. Test simulations with an additional set of 12 α-helical proteins demonstrated that this force field performed better on α-helical proteins than the previous parametrizations of UNRES. The proposed approach is applicable to any problem of maximum-likelihood parameter estimation when the contributions to the maximum-likelihood function cannot be evaluated at the experimental points and the dimension of the configurational space is too high to construct histograms of the experimental distributions.

Gem1 and ERMES do not directly affect phosphatidylserine transport from ER to mitochondria or mitochondrial inheritance.

In yeast, a protein complex termed the ER-Mitochondria Encounter Structure (ERMES) tethers mitochondria to the endoplasmic reticulum. ERMES proteins are implicated in a variety of cellular functions including phospholipid synthesis, mitochondrial protein import, mitochondrial attachment to actin, polarized mitochondrial movement into daughter cells during division, and maintenance of mitochondrial DNA (mtDNA). The mitochondrial-anchored Gem1 GTPase has been proposed to regulate ERMES functions. Here, we show that ERMES and Gem1 have no direct role in the transport of phosphatidylserine (PS) from the ER to mitochondria during the synthesis of phosphatidylethanolamine (PE), as PS to PE conversion is not affected in ERMES or gem1 mutants. In addition, we report that mitochondrial inheritance defects in ERMES mutants are a secondary consequence of mitochondrial morphology defects, arguing against a primary role for ERMES in mitochondrial association with actin and mitochondrial movement. Finally, we show that ERMES complexes are long-lived, and do not depend on the presence of Gem1. Our findings suggest that the ERMES complex may have primarily a structural role in maintaining mitochondrial morphology.

Neural and Onconeural Autoantibodies and Blood-Brain Barrier Disruption Markers in Patients Undergoing Radiotherapy for High-Grade Primary Brain Tumour.

Radiotherapy (RT) plays a key role in brain tumours but can negatively impact functional outcomes and quality of life. The aim of this study was to analyse anti-neural and onconeural autoantibodies and markers of blood-brain barrier (BBB) disruption in patients with primary brain cancer undergoing RT. MATERIALS AND METHODS: A prospective study was conducted on 45 patients with a brain tumour scheduled for intensity-modulated radiotherapy. Assessments were performed at baseline, post-RT, and at three months. We measured serum levels of BBB disruption biomarkers and anti-neural, onconeural, and organ-specific antibodies. RESULTS: Antibodies against nucleosome antigens and neuronal surface antigens were detected in 85% and 3% of cases, respectively; anti-neural and onconeural antibodies were observed in 47% and 5.8%. In 44% patients, ≥2 antibody types were detected. No significant changes in BBB biomarkers were observed. CONCLUSION: The findings of this study show that a humoral immune response is common in patients undergoing RT for brain cancer. This response appears to be non-organ specific but rather directed against nucleosome antigens, but onconeural antibodies were uncommon, suggesting a low risk of a neurological paraneoplastic syndrome. Our data suggested that radiotherapy may not affect BBB integrity, but larger studies are needed to better characterise the pathophysiological effects of RT.

Maternal SARS-CoV-2 Infection at Delivery Increases IL-6 Concentration in Umbilical Cord Blood.

BACKGROUND: SARS-CoV-2 infection in pregnant women may induce inflammation within the amniotic cavity and/or an increase in proinflammatory cytokines in fetal circulation. The aim was to investigate levels of IL-6 in maternal blood, umbilical cord blood, and amniotic fluid in pregnant women infected with SARS-CoV-2 at delivery. METHODS: A single-center prospective observational case-control study of pregnant women diagnosed with SARS-CoV-2 infection at delivery was conducted. A total of 48 infected and 42 healthy women had IL-6 concentrations measured in their blood, amniotic fluid, and umbilical cord blood. RESULTS: The concentrations of IL-6 in maternal blood and amniotic fluid were similar in the study and control groups, while umbilical cord blood concentrations were significantly higher in SARS-CoV-2-positive women. The umbilical cord blood IL-6 concentration was related to composite neonatal morbidity. CONCLUSIONS: Maternal SARS-CoV-2 infection in pregnant women at delivery increases umbilical cord blood IL-6 concentration. The correlation between maternal and umbilical blood concentrations indicates a possibility of passage of IL-6 through the placenta. Perinatal alterations resulting from maternal SARS-CoV-2 infection at delivery carry a risk of impacting the health of infants even in asymptomatic course of infection.

The influence of various endocrine disruptors on the reproductive system.

Various stimulants (VS) are chemicals that disrupt the endocrine system - endocrine homeostasis of the reproductive system - which also known as endocrine-disrupting chemicals (EDCs). These substances are found in the human body, in both the blood and urine, amniotic fluid, or, among others, the adipose tissue. This article presents the current state of knowledge of the effect of EDCs and additional factors such as smoking, alcohol consumption, and cannabis on the gonads. The article is an overview of the impact of EDCs and their mechanism of action, with particular emphasis on gonads, based on databases such as PubMed, EMBASE and Google Scholar, and Web of Science available until May 2022. The impact of human exposure to bisphenol A (BPA) is not fully understood, but it has been shown that phthalates show a negative correlation in anti-androgenic activity in the case of men and women for the anti-Müllerian hormone (AMH). Smoking cigarettes and passive exposure to tobacco have a huge impact on the effects of endocrine disorders in both women and men, especially during the reproductive time. Also, the use of large amounts of cannabinoids during the reproductive years can lead to similar disorders. It has been documented that excessive alcohol consumption leads to disturbed function of the hypothalamus-pituitary-gonadal axis (HPG). Excess caffeine consumption may adversely affect male reproductive function, although this is not fully proven. Therefore, the following publication presents various stimulants (BPA, phthalates, nicotine, alcohol, cannabis) that disrupt the function of the endocrine system and, in particular, affect the function of the gonads.

Chaperones in control of protein disaggregation.

The chaperone protein network controls both initial protein folding and subsequent maintenance of proteins in the cell. Although the native structure of a protein is principally encoded in its amino-acid sequence, the process of folding in vivo very often requires the assistance of molecular chaperones. Chaperones also play a role in a post-translational quality control system and thus are required to maintain the proper conformation of proteins under changing environmental conditions. Many factors leading to unfolding and misfolding of proteins eventually result in protein aggregation. Stress imposed by high temperature was one of the first aggregation-inducing factors studied and remains one of the main models in this field. With massive protein aggregation occurring in response to heat exposure, the cell needs chaperones to control and counteract the aggregation process. Elimination of aggregates can be achieved by solubilization of aggregates and either refolding of the liberated polypeptides or their proteolysis. Here, we focus on the molecular mechanisms by which heat-shock protein 70 (Hsp70), Hsp100 and small Hsp chaperones liberate and refold polypeptides trapped in protein aggregates.

Comparison of Skinfold Thickness Measured by Caliper and Ultrasound Scanner in Normative Weight Women.

Obesity is a major issue affecting not only adults but also children in many places of the world. There are numerous methods for estimating the body fat percentage, however, all of those methods are different in terms of availability, accuracy, and the cost of an individual examination. The aim of this study was to compare two relatively easy and widespread measurement methods for assessing skinfold thickness: the BodyMetrix BX2000 ultrasound machine and a classic GPM caliper. Fifty-eight young women aged 19-24 years with normative body weight participated in the study. We found that although the measurements performed by both methods are positively correlated, the obtained values were different. In seven out of nine measured points, these differences were statistically significant. The measurements of skin fat folds with a caliper showed a higher value of subcutaneous tissue compared to ultrasound measurements. Only the values of measurements on the pectoral and mid-axillary did not differ between the methods. We conclude that due to the significant discrepancies in the values of measured skinfold thickness, appropriate measurement tools and dedicated formulas estimating the amount of body fat should be used.

Identification of the epitope for anti-cystatin C antibody.

Human cystatin C (hCC), like many other amyloidogenic proteins, has been shown to form dimers by exchange of subdomains of the monomeric protein. Considering the model of hCC fibrillogenesis by propagated domain swapping, it seems possible that inhibition of this process should also suppress the entire process of dimerization and fibrillogenesis which leads to specific amyloidosis (hereditary cystatin C amyloid angiopathy (HCCAA)). It was reported that exogenous agents like monoclonal antibody against cystatin C are able to suppress formation of cystatin C dimers. In the effort to find a way of controlling the cystatin fibrillization process, the interactions between monoclonal antibody Cyst-13 and cystatin C were studied in detail. The present work describes the determination of the epitope of hCC to a monoclonal antibody raised against cystatin C, Cyst-13, by MALDI mass spectrometry, using proteolytic excision of the immune complex. The shortest epitope sequence was determined as hCC(107-114). Affinity studies of synthetic peptides revealed that the octapeptide with epitope sequence does not have binding ability to Cyst-13, whereas its longer counterpart, hCC(105-114), binds the studied antibody. The secondary structure of the peptides with epitope sequence was studied using circular dichroism and NMR spectroscopy.

Fungicidal amphotericin B sponges are assemblies of staggered asymmetric homodimers encasing large void volumes.

Amphotericin B (AmB) is a powerful but toxic fungicide that operates via enigmatic small molecule-small molecule interactions. This mechanism has challenged the frontiers of structural biology for half a century. We recently showed AmB primarily forms extramembranous aggregates that kill yeast by extracting ergosterol from membranes. Here, we report key structural features of these antifungal 'sponges' illuminated by high-resolution magic-angle spinning solid-state NMR, in concert with simulated annealing and molecular dynamics computations. The minimal unit of assembly is an asymmetric head-to-tail homodimer: one molecule adopts an all-trans C1-C13 motif, the other a C6-C7-gauche conformation. These homodimers are staggered in a clathrate-like lattice with large void volumes similar to the size of sterols. These results illuminate the atomistic interactions that underlie fungicidal assemblies of AmB and suggest this natural product may form biologically active clathrates that host sterol guests.

Mechanism of formation of the C-terminal beta-hairpin of the B3 domain of the immunoglobulin binding protein G from Streptococcus. III. Dynamics of long-range hydrophobic interactions.

A 20-residue peptide, IG(42-61), derived from the C-terminal beta-hairpin of the B3 domain of the immunoglobulin binding protein G from Streptoccocus was studied using circular dichroism, nuclear magnetic resonance (NMR) spectroscopy at various temperatures and by differential scanning calorimetry (DSC). Unlike other related peptides studied so far, this peptide displays two heat capacity peaks in DSC measurements (at a scanning rate of 1.5 deg/min at a peptide concentration of 0.07 mM), which suggests a three-state folding/unfolding process. The results from DSC and NMR measurements suggest the formation of a dynamic network of hydrophobic interactions stabilizing the structure, which resembles a beta-hairpin shape over a wide range of temperatures (283-313 K). Our results show that IG (42-61) possesses a well-organized three-dimensional structure stabilized by long-range hydrophobic interactions (Tyr50 ... Phe57 and Trp48 ... Val59) at T = 283 K and (Trp48 ... Val59) at 305 and 313 K. The mechanism of beta-hairpin folding and unfolding, as well as the influence of peptide length on its conformational properties, are also discussed.

Assessment of Impact of Aramid Fibre Addition on the Mechanical Properties of Selected Asphalt Mixtures.

Various additives to asphalt binders and asphalt mixtures improving their properties are being used more and more frequently in order to improve the durability of road pavements. Such additives include various types of fibres, including aramid fibres. Tests concerning the impact of aramid fibre addition on the properties of selected asphalt mixtures have been described herein. Two types of asphalt mixtures were assessed: high modulus asphalt concrete (HMAC) and stone mastic asphalt (SMA). The examined asphalt mixtures were assessed with regard to: resistance to rutting, resistance to water and frost as well as fatigue resistance. The conducted tests showed relatively small impact of aramid fibre addition on the improvement of some assessed properties of the analysed asphalt mixtures. The obtained results were also compared to results of the tests conducted by the other research team concerning the impact of aramid fibre addition on the properties of the other types of asphalt mixtures.

Psychiatric disorders and changes in immune response in labor and postpartum.

Women may present with psychiatric disorders during pregnancy, normal labor, following delivery by caesarean section, or in the postpartum period. The accumulating evidence suggests that these disorders may be due to changes in immune responses. During pregnancy complications such as the prolongation of cervical ripening or descent, placental abruption, premature labor, and preeclampsia increase the risk of postpartum psychiatric disorders. Women may exhibit depression and postpartum psychosis following either normal birth or caesarean section. Since psychiatric disorders like schizophrenia, major depression, and bipolar disorder are associated with both alterations in the immune response and changes in immune cell subpopulations, in this study we have chosen to examine whether the psychiatric disorders in women during labor or postpartum also lead to aberrant immune responses.

Wilms' tumor 1 antigen immunoreactivity in epithelial ovarian cancer - diagnostic and prognostic value.

OBJECTIVES: Ovarian cancer is a heterogeneous disease, with a number of different histological subtypes with various responses to treatment. Wilms' tumor 1 (WT1) immunoreactivity is used to distinguish between OC's various subtypes. However, little is known about the protein's role as a prognostic factor. Thus, the main aim of our study was to evaluate the relationship between WT1 expression and patient overall survival (OS) and lymph node metastases. MATERIALS AND METHODS: Study group consisted of 164 women aged 22-84, diagnosed with epithelial ovarian cancer (EOC). WT1 expression in histological slides was assessed by immunohistochemistry. RESULTS: Serous tumors were the most common subtype among EOC (n = 126; 76.8%), followed by endometrioid (n = 20; 12.2%), clear-cell (n = 14; 8.5%) and mucinous cancer (n = 4; 2.4%). Of all serous EOC, WT1-positive tumors accounted for 75.6% of cases and this number was significantly higher than in other histological subtypes (p < 0.0001). Patients with lymph node metastases were more likely to have WT1-positive than WT1-negative tumors (p = 0.006). There was no significant correlation between WT1 immunoreactivity and OS across the whole study group of EOC patients (p = 0.6); however, in the group of non-serous (mucinous, endometrioid and clear-cell) EOC subjects, WT1 immunoreactivity was associated with shorter OS (p = 0.046). CONCLUSIONS: WT1 immunoreactivity may be helpful in differentiating primary epithelial serous carcinomas from non-serous ovarian cancers; however, its prognostic role in EOC is rather uncertain.

Maintenance and stabilization of mtDNA can be facilitated by the DNA-binding activity of Ilv5p.

Mitochondrial DNA (mtDNA) is inherited as a protein-DNA complex (the nucleoid). Proteins associated with the nucleoid are not only components directly involved in maintenance and propagation of mtDNA but can also be bi-functional enzymes whose metabolic activities are not directly related to mtDNA stability. In the yeast Saccharomyces cerevisiae, one such enzyme, Ilv5p is required for branch chain amino acid biosynthesis but also associates with the nucleoid. Deletions of ILV5 lead not only to metabolic defects but also to destabilization of mtDNA. Further, minor overproduction of Ilv5p stabilizes mtDNA in strains lacking Abf2p, a major mtDNA binding and packaging protein. Here we show that Ilv5p binds double-stranded DNA in vitro and is unaffected by the presence of saturating concentrations of Abf2p. In cells lacking Abf2p the amount of Ilv5p associated with the nucleoid increases significantly and is proportional to the mitochondrial concentration of Ilv5p. Altogether, we conclude that direct binding of Ilv5p can aid in the maintenance and stabilization of mtDNA.