Chitinase production by Beauveria felinaRD 101: optimization of parameters under solid substrate fermentation conditions

Major parameters affecting the production of chitinase by Beauveria felinaRD 101 under solid substrate fermentation conditions have been optimized. Wheat bran moistened with 100 MS-HCl medium adjusted to pH 5.0, inoculated with 1 × 10¹⁰ conidia g^–1 initial dry bran and incubated at 28 °C for 6 days produced maximum chitinase activity of 6.34 U g^–1 initial dry substrate.     

Synthesis, DNA binding, and cytotoxicity studies of pyrrolo[2,1-c][1,4]benzodiazepine-anthraquinone conjugates

A series of pyrrolo[2,1-c][1,4]benzodiazepine-anthraquinone conjugates have been prepared and evaluated for their DNA binding ability as well as anticancer activity. Some of these molecules have shown significant anticancer activity in a number of cancer cell lines.     

Tuning genetic clocks employing DNA binding sites

Periodic oscillations play a key role in cell physiology from the cell cycle to circadian clocks. The interplay of positive and negative feedback loops among genes and proteins is ubiquitous in these networks. Often, delays in a negative feedback loop and/or degradation rates are a crucial mechanism to obtain sustained oscillations. How does nature control delays and kinetic rates in feedback networks? Known mechanisms include proper selection of the number of steps composing a feedback loop and alteration of protease activity, respectively. Here, we show that a remarkably simple means to control both delays and effective kinetic rates is the employment of DNA binding sites. We illustrate this design principle on a widely studied activator-repressor clock motif, which is ubiquitous in natural systems. By suitably employing DNA target sites for the activator and/or the repressor, one can switch the clock “on” and “off” and precisely tune its period to a desired value. Our study reveals a design principle to engineer dynamic behavior in biomolecular networks, which may be largely exploited by natural systems and employed for the rational design of synthetic circuits.     

Analogs of N'-hydroxy-N-(4H,5H-naphtho[1,2-d]thiazol-2-yl)methanimidamide inhibit Mycobacterium tuberculosis methionine aminopeptidases

Our previous target validation studies established that inhibition of methionine aminopeptidases (MtMetAP, type 1a and 1c) from Mycobacterium tuberculosis (Mtb) is an effective approach to suppress Mtb growth in culture. A novel class of MtMetAP1c inhibitors comprising of N'-hydroxy-N-(4H,5H-naphtho[1,2-d]thiazol-2-yl)methanimidamide (4c) was uncovered through a high-throughput screen (HTS). A systematic structure-activity relationship study (SAR) yielded variants of the hit, 4b, 4h, and 4k, bearing modified A- and B-rings as potent inhibitors of both MtMetAPs. Except methanimidamide 4h that showed a moderate Mtb inhibition, a desirable minimum inhibitory concentration (MIC) was not obtained with the current set of MtMetAP inhibitors. However, the SAR data generated thus far may prove valuable for further tuning of this class of inhibitors as effective anti-tuberculosis agents.     

A pilot study of an anti-endotoxin Ig-enriched bovine colostrum to prevent experimental sepsis

Despite the dramatic increase in antimicrobial resistance, there is a dearth of antibiotics in development and few pharmaceutical companies working in the field. Further, any new antibiotics are likely to have a short shelf life. Ab-based interventions offer alternatives that are not likely to be circumvented by the widely prevalent antibiotic resistance genes. Bovine colostrum (BC)—the first milk after parturition, rich in nutrients and immune components—promotes gut integrity and modulates the gut microbiome. We developed a hyperimmune BC (HBC) enriched in Abs to a highly conserved LOS core region of Gram-negative bacteria by immunizing pregnant cows with a vaccine comprised of detoxified LOS from Escherichia coli O111 Rc (J5) mutant non-covalently complexed to group B meningococcal outer membrane protein (J5dLOS/OMP). This vaccine generated robust levels of anti-J5 LOS Ab in the colostrum. When given orally to neutropenic rats challenged orally with Pseudomonas aeruginosa, administration of HBC improved survival compared to non-immune rats, while both BC preparations improved survival compared to PBS controls. Elevated circulating endotoxin levels correlated with mortality. HBC and to a lesser extent non-immune BC reduced bacterial burden from the liver, lung, and spleen. We conclude that HBC and to a lesser extent BC may be effective supplements that improve outcome from lethal gut-derived disseminated infection and may reduce transmission of Gram-negative bacilli from the gastrointestinal tract.     

Risk of Ovarian Cancer and Inherited Variants in Relapse-Associated Genes

Background

We previously identified a panel of genes associated with outcome of ovarian cancer. The purpose of the current study was to assess whether variants in these genes correlated with ovarian cancer risk.

Methods and Findings

Women with and without invasive ovarian cancer (749 cases, 1,041 controls) were genotyped at 136 single nucleotide polymorphisms (SNPs) within 13 candidate genes. Risk was estimated for each SNP and for overall variation within each gene. At the gene-level, variation within MSL1 (male-specific lethal-1 homolog) was associated with risk of serous cancer (p = 0.03); haplotypes within PRPF31 (PRP31 pre-mRNA processing factor 31 homolog) were associated with risk of invasive disease (p = 0.03). MSL1 rs7211770 was associated with decreased risk of serous disease (OR 0.81, 95% CI 0.66–0.98; p = 0.03). SNPs in MFSD7, BTN3A3, ZNF200, PTPRS, and CCND1A were inversely associated with risk (p<0.05), and there was increased risk at HEXIM1 rs1053578 (p = 0.04, OR 1.40, 95% CI 1.02–1.91).

Conclusions

Tumor studies can reveal novel genes worthy of follow-up for cancer susceptibility. Here, we found that inherited markers in the gene encoding MSL1, part of a complex that modifies the histone H4, may decrease risk of invasive serous ovarian cancer.     

Association of CYP3A5*3 polymorphism with development of acute leukemia

BACKGROUND:

CYP3A5 was observed to be an important genetic contributor to inter individual differences in CYP3A-dependent drug metabolism in acute leukemic patients. Loss of CYP3A5 expression was mainly conferred by a single nucleotide polymorphism at 6986A>G (CYP3A5*3). We investigated the association between CYP3A5*3 polymorphism and acute leukemia.

MATERIALS AND METHODS:

Two hundred and eighty nine acute leukemia cases comprising of 145 acute lymphocytic leukemia (ALL), 144 acute myeloid leukemia and 241 control samples were analyzed for CYP3A5*3 polymorphism using PCR-RFLP method. Statistical analysis was performed with SPSS version (15.0) to detect the association between CYP3A5*3 polymorphism and acute leukemia.

RESULTS:

The CYP3A5*3 polymorphism 3/3 genotype was significantly associated with acute leukemia development (χ²- 133.53; df-2, P 0.000). When the data was analyzed with respect to clinical variables, mean WBC, blast % and LDH levels were increased in both ALL and AML cases with 3/3 genotype. The epidemiological variables did not contribute to the genotype risk to develop either AML or ALL.

CONCLUSION:

The results suggest that the CYP3A5*3 polymorphism might confer the risk to develop ALL or AML emphasizing the significance of effective phase I detoxification in carcinogenesis. Association of the polymorphism with clinical variables indicate that the 3/3 genotype might also contribute to poorer survival of the patients.     

The Galectin CvGal1 from the Eastern Oyster (Crassostrea virginica) Binds to Blood Group A Oligosaccharides on the Hemocyte Surface

The galectin CvGal1 from the eastern oyster (Crassostrea virginica), which possesses four tandemly arrayed carbohydrate recognition domains, was previously shown to display stronger binding to galactosamine and N-acetylgalactosamine relative to d-galactose. CvGal1 expressed by phagocytic cells is “hijacked” by the parasite Perkinsus marinus to enter the host, where it proliferates and causes systemic infection and death. In this study, a detailed glycan array analysis revealed that CvGal1 preferentially recognizes type 2 blood group A oligosaccharides. Homology modeling of the protein and its oligosaccharide ligands supported this preference over type 1 blood group A and B oligosaccharides. The CvGal ligand models were further validated by binding, inhibition, and competitive binding studies of CvGal1 and ABH-specific monoclonal antibodies with intact and deglycosylated glycoproteins, hemocyte extracts, and intact hemocytes and by surface plasmon resonance analysis. A parallel glycomic study carried out on oyster hemocytes (Kurz, S., Jin, C., Hykollari, A., Gregorich, D., Giomarelli, B., Vasta, G. R., Wilson, I. B. H., and Paschinger, K. (2013) J. Biol. Chem. 288,) determined the structures of oligosaccharides recognized by CvGal1. Proteomic analysis of the hemocyte glycoproteins identified β-integrin and dominin as CvGal1 “self”-ligands. Despite strong CvGal1 binding to P. marinus trophozoites, no binding of ABH blood group antibodies was observed. Thus, parasite glycans structurally distinct from the blood group A oligosaccharides on the hemocyte surface may function as potentially effective ligands for CvGal1. We hypothesize that carbohydrate-based mimicry resulting from the host/parasite co-evolution facilitates CvGal1-mediated cross-linking to β-integrin, located on the hemocyte surface, leading to cell activation, phagocytosis, and host infection.