Stimulating the hunger of enzymes: The design of an ionic liquid that have the ability to dissolve cellulose has been attempted from the viewpoint of a cellulase. N,N-diethyl-N-(2-methoxyethyl)-N-methylammonium alanine ([N(221ME) ][Ala]) is a good solvent for cellulose. Dissolution in [N(221ME) ][Ala] converts the crystalline structure of cellulose from Type I to ...

Man(α1-6)[GlcNAc(β1-2)Man(α1-3)]ManGlcNAc2 is a key branch point intermediate in the insect N-glycosylation pathway because it can be either trimmed by a processing β-N-acetylglucosaminidase (FDL) to produce paucimannosidic N-glycans or elongated by N-acetylglucosaminyltransferase II (GNT-II) to produce complex N-glycans. N-acetylglucosaminyltransferase I (GNT-I) contributes to branch point intermediate production and can potentially reverse ...

Fe(II)/α-ketoglutarate dependent oxygenases are versatile catalysts associated with a number of different biological functions, in which they use the oxidizing power of activated dioxygen to convert a variety of substrates. A mononuclear non-heme iron center is used to couple the decarboxylation of the cosubstrate α-ketoglutarate with a two-electron oxidation of ...

In the design of inhibitors of phosphosugar metabolizing enzymes and receptors with therapeutic interest, malonate has been reported in a number of cases as a good and hydrolytically-stable surrogate of the phosphate group, since both functions are dianionic at physiological pH and of comparable size. We have investigated a series ...

Reducing angiotensin II (Ang II) production via angiotensin-converting enzyme (ACE) inhibitors is a key approach for the treatment of hypertension. However, these inhibitors may also affect other enzymes, such as angiotensinases and vasopressinase, responsible for the metabolism of other peptides also involved in blood pressure control, such as Ang 2-10, ...

Here we report the isolation of carboxypeptidases A1 and A2 (CPA1 and CPA2) from the rat mesenteric arterial bed perfusate, which were found to be identical with their pancreatic counterparts. Angiotensin (Ang) I, Ang II, Ang-(1-9) and Ang-(1-12) were differentially processed by these enzymes, worthy mentioning the peculiar CPA1-catalyzed conversion ...

In mammals, xanthine oxidoreductase can exist as xanthine dehydrogenase (XDH) and xanthine oxidase (XO). The two enzymes possess common redox active cofactors, which form an electron transfer (ET) pathway terminated by a flavin cofactor. In spite of identical protein primary structures, the redox potential difference between XDH and XO for ...

The possible sulfatase activity of several carbonic anhydrase (CA, EC 4.2.1.1) isoforms have been investigated with a series of synthesized methanesulfonate derivatives of phenols. Four α-CA isozymes, i.e. hCA I, hCA II, hCA IV and hCA VI (h = human isoform), were included in the study. We evidenced that the original sulfonate ...

Quercetin dioxygenase (QDO) catalyzes the oxidation of the flavonol quercetin with dioxygen, cleaving the central heterocyclic ring and releasing CO. The QDO from Bacillus subtilis is unusual in that it has been shown to be active with several divalent metal cofactors such as Fe, Mn, and Co. Previous comparison of ...

Adenine deaminase (ADE) from the amidohydrolase superfamily (AHS) of enzymes catalyzes the conversion of adenine to hypoxanthine and ammonia. Enzyme isolated from Escherichia coli was largely inactive toward the deamination of adenine. Molecular weight determinations by mass spectrometry provided evidence that multiple histidine and methionine residues were oxygenated. When iron ...

Carbonic anhydrases (CA) catalyze activated ester hydrolysis in addition to the hydration of CO(2) to bicarbonate. They also show phosphatase activity with 4-nitrophenyl phosphate as substrate but not sulfatase with the corresponding sulfate. Here we prove that the enzyme is catalyzing the synthesis of cyclic diols from sulfate esters. 5-, ...

The severe pediatric disorder, mucolipidosis II (ML-II; I-cell disease), is caused by defects in mannose 6-phosphate (Man-6-P) biosynthesis. Patients with ML-II exhibit multiple developmental defects including skeletal, craniofacial and joint abnormalities. To date, the molecular mechanisms that underlie these clinical manifestations are poorly understood. Taking advantage of a zebrafish model ...

Ginseng (Panax ginseng C.A. Meyer) is one of the most popular medicinal herbs and contains pharmacologically active components, ginsenosides, in their roots. Ginsenosides, a class of tetracyclic triterpene saponins, are thought to be synthesized from dammarenediol-II after hydroxylation by the cytochrome P450 (CYP) enzyme and then glycosylation by glycosyltransferase (GT). ...

Topoisomerases are essential enzymes involved in all processes of DNA metabolism, and their inhibitors have been identified as potential anticancer agents. The present study examined the effect of nine polyphenolic compounds derived from parts of two unique varieties of the Leguminosae, Vicia faba and Lotus edulis, on the activity of ...

The biosynthesis of GTP derived metabolites such as tetrahydrofolate (THF), biopterin (BH4), and the modified tRNA nucleosides queuosine (Q) and archaeosine (G+) relies on several enzymes of the Tunnel-fold superfamily. A subset of these proteins include the 6-pyruvoyl-tetrahydropterin (PTPS-II), PTPS-III, and PTPS-I homologs, all members of the COG0720 family, that ...

3-Deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAHPS), the first enzyme of the shikimate pathway, is responsible for the synthesis of aromatic amino acids in microorganisms and plants. The pathway has been of increasing interest in the recent past as the enzymes are being targeted for antimicrobial drug and herbicide design. In the present ...

In nucleic acid polymerization reaction, pyrophosphorolysis is the reversal of nucleotide addition, in which the terminal nucleotide is excised in the presence of inorganic pyrophosphate (PPi). The CCA enzymes are unusual RNA polymerases, which catalyze CCA addition to positions 74-76 at the tRNA 3' end without using a nucleic acid ...

This study reinvestigated the synthesis of cellulose in vitro with a well-known cellulose-producing bacterium, Gluconacetobacter xylinus. Alkylmaltoside detergents, which are more frequently used in recent structural biological researches, are uniquely used in this study to solubilize cellulose-synthesizing activity from the cell membrane of G. xylinus. Activity comparable to that previously ...

The mercury (II) ion is toxic and is usually detoxified in Bacteria by reduction to elemental mercury, which is less toxic. This is catalysed by an NAD(P)H-dependent mercuric reductase (EC 1.16.1.1). Here, we present strong evidence that Methylococcus capsulatus (Bath) - a methanotrophic member of the Gammaproteobacteria - uses this ...

The early steps of glycoprotein biosynthesis involve processing of the N-glycan core by endoplasmic reticulum α-glucosidases I and II which sequentially trim the outermost α1,2-linked and the two more internal α1,3-linked glucose units, respectively. We have demonstrated the presence of some components of the enzymic machinery required for glycoprotein synthesis ...

A putative Type II restriction-modification system of Thermotoga neapolitana, TneDI, was cloned into Escherichia coli XL1-Blue MRF' and characterized. Gene CTN_0339 specifies the endonuclease R.TneDI, while CTN_0340 encodes the cognate DNA methyltransferase M.TneDI. Both enzymes were purified simply by heating the cell lysates of E. coli followed by centrifugation. The ...

In plant cells, boron (B) occurs predominantly as a borate ester associated with the rhamnogalacturonan II (RG-II) complex, but the function of this B-RG-II complex has yet to be investigated. 3-Deoxy-D-manno-2-octulosonic acid (KDO) is a specific component monosaccharide of RG-II. Mutant plants defective in KDO biosynthesis are expected to have ...

A deeper mechanistic understanding of the saccharification of cellulosic biomass could enhance the efficiency of biofuels development. We report here the real-time visualization of crystalline cellulose degradation by individual cellulase enzymes through use of an advanced version of high-speed atomic force microscopy. Trichoderma reesei cellobiohydrolase I (TrCel7A) molecules were observed ...

Difructose anhydride III (DFA III), the smallest cyclic disaccharide, consists of two fructose residues. DFA III is a hydrolysate of inulin and is rarely found in nature. Industrial interest in DFA III as a low-calorie sugar substitute is increasing. The present review describes the properties and physiological functions of DFA ...

The recent discovery of heterozygous isocitrate dehydrogenase 2 (IDH2) mutations of residue Arg(140) to Gln(140) or Gly(140) (IDH2(wt/R140Q), IDH2(wt/R140G)) in d-2-hydroxyglutaric aciduria (D-2-HGA) has defined the primary genetic lesion in 50% of D-2-HGA patients, denoted type II. Overexpression studies with IDH1(R132H) and IDH2(R172K) mutations demonstrated that the enzymes acquired a ...

In this paper we studied the mechanism of formation of the internal aldimine, a common intermediate to most PLP-dependent enzymes. A large model based on the crystal structure from the human Ornithine Decarboxylase (ODC) enzyme was constructed, and in total accounts with 504 atoms. The reaction mechanism was investigated using ...

Leishmania infantum glyoxalase II shows absolute specificity towards its trypanothione thioester substrate. In the previous work, we performed a comparative analysis of glyoxalase II structures determined by X-ray crystallography which revealed that Tyr291 and Cys294, absent in the human homologue, are essential for substrate binding. To validate this trypanothione specificity ...

A cross-linked mutant endoglucanase II was prepared for enzymatic polymerization to cellulose. The cross-linked enzyme is composed of three mutant enzymes showing polymerization activity. A characteristic feature of the polymerization with this cross-linked enzyme is formation of cellulose fibrils in contrast to plate-like crystals obtained by using a free enzyme.

We purified eel hatching enzyme (EHE) from the hatching liquid of Japanese eel Anguilla japonica belonging to Elopomorpha to a single band on SDS-PAGE. TOF-MS analysis revealed that the purified EHE contained several isozymes with similar molecular masses. Comparison of the egg envelope digestion specificities of the purified EHE and ...

In this issue of Molecular Cell, two papers on the structure of murine capping enzyme guanylyltransferase (Ghosh et al., 2011) and yeast studies of the recognition of the RNA polymerase II CTD (Schwer and Shuman, 2011) describe the mechanism of recruitment of the capping apparatus to nascent pre-mRNAs.

The development of a general 1-Zn(II) nucleoside diphosphate (NDP) sensor assay for rapid evaluation of glycosyltransferase (GT) activity is described. The 1-Zn(II) NDP sensor assay offers submicromolar sensitivity, compatibility with both purified enzymes and crude cell extracts, and exquisite selectivity for NDPs over the corresponding NDP-sugars. Thus, the 1-Zn(II) NDP ...

Fructose 1,6-bisphosphate (FBP) aldolase has been used as biocatalyst in the synthesis of several pharmaceutical compounds such as monosaccharides and analogs. Is has been suggested that microbial metal-dependant Class II aldolases could be better industrial catalysts than mammalian Class I enzyme because of their greater stability. The Class II aldolases ...

The present study describes the purification and characterization of a hyaluronidase (DRHyal-II) from Daboia/Vipera russelli venom and its inhibition by β-3-(3-hydroxy-4-oxopyridyl) α-amino-propionic acid, the mimosine. Gel permeation and ion exchange chromatography were employed to isolate DRHyal-II. The molecular mass by MALDI-TOF mass spectrometry was found to be 28.3 kDa. Single ...

Purification of biotechnologically important proteins is of vital interest to the biotech industry. β-Glucosidases, belonging to Family 1 and Family 3 of the glycosylhydrolases, have varied applications as carbohydrate hydrolyzing and synthesizing enzymes. Obtaining high quantities of these enzymes is important for exploring their biosynthetic potential, structural information and catalytic ...

An acidic Cel6A, cellobiohydrolase (CBH) II, was purified from Penicillium decumbens and designated as PdCel6A. The deduced internal amino acid sequence of the novel CBH has a high degree of sequence identity with the CBH II from Aspergillus fumigatus. Surprisingly, PdCel6A exhibits characteristics comparable to that of CBH I, as ...

The in vitro effects of the anabolic compounds, zeranol, 17 β-estradiol, diethylstilbestrol (DES), and trenbolone, on the activity of purified human carbonic anhydrase I and II were evaluated. In vitro CA enzyme activity was determined colorimetrically using the CO(2) hydration method of Maren. IC(50) values of the compounds that caused ...

The ADAR enzymes catalyze conversion of adenosine to inosine in double-stranded RNA. A positive effect of ADAR1 on HIV-1 replication has recently been reported. Here, we show that another ADAR enzyme, ADAR2, positively affects the replication process of HIV-1. We found that, analogously to ADAR1, ADAR2 enhances the release of ...

More than fifteen years after the first identification of a class II isoform of phosphoinositide 3-kinase (PI3K) in Drosophila melanoǵaster this subfamily remains the most enigmatic among all PI3Ks. What are the functions of these enzymes? What are their mechanisms of activation? Which downstream effectors are specifically regulated by these ...

Previously, we have reported the presence of highly sulfated dermatans in solitary ascidians from the orders Phlebobranchia (Phallusia nigra) and Stolidobranchia (Halocynthia pyriformis and Styela plicata). Despite the identical disaccharide backbone, consisting of [→4IdoA(2S)β-1→3GalNAcβ-1→], those polymers differ in the position of sulfation on the N-Acetyl galactosamine, which can occur at ...

Since angiotensin-(1-12) [Ang-(1-12)] is a non-renin dependent alternate precursor for the generation of cardiac Ang peptides in rat tissue, we investigated the metabolism of Ang-(1-12) by plasma membranes (PM) isolated from human atrial appendage tissue from nine patients undergoing cardiac surgery for primary control of atrial fibrillation (MAZE surgical procedure). ...

The glucose Enzyme II transporter complex of the Escherichia coli phosphotransferase system (PTS) exists in at least two physically distinct forms: a membrane-integrated dimeric form, and a cytoplasmic monomeric form, but little is known about the physical states of these enzyme forms. Six approaches were used to evaluate protein-protein and ...

Wheat RNA ligase can be dissected into three isolated domain enzymes that are responsible for its core ligase, 5'-kinase, and 2',3'-cyclic phosphate 3'-phosphodiesterase activities, respectively. In the present study, we pursued a practical strategy using the domain enzymes for in vitro step-by-step ligation of RNA molecules. As a part of ...

Although enzymes responsible for the cyclization of amino-terminal glutamine residues are present in both plant and mammal species, none have yet been characterized in bacteria. Based on low sequence homologies to plant glutaminyl cyclases (QCs), we cloned the coding sequences of putative microbial QCs from Zymomonas mobilis (ZmQC) and Myxococcus ...

The first committed step in triterpenoid biosynthesis is the cyclization of epoxysqualene into various triterpene alcohol isomers, a reaction catalyzed by oxidosqualene cyclases (OSCs). The different OSCs have characteristic product specificities, which are mainly due to differences in the numbers of high-energy intermediates the enzymes can stabilize. The goal of ...

Stable operation of photosynthesis is based on the establishment of local equilibria of metabolites in the Calvin cycle. This concerns especially equilibration of stromal contents of adenylates and pyridine nucleotides and buffering of CO(2) concentration to prevent its depletion at the sites of Rubisco. Thermodynamic buffering that controls the homeostatic ...

In mammals and yeasts, oxidosqualene cyclase (OSC) catalyzes the formation of lanosterol, the first cyclic intermediate in sterol biosynthesis. We used a murine myeloma cell line (NS0), deficient in the 17β-hydroxysteroid dehydrogenase type 7 (HSD17B7), as a model to study the potential interaction of the HSD17B7 with the OSC in ...

Cyclic AMP is an important intracellular signaling molecule participating e.g. in sensory signal transduction, cardiac myocyte regulation, learning and memory. The formation of cAMP is catalyzed by adenylyl cyclases. A variety of factors can modulate the properties of these enzymes and lead to dynamic changes of the intracellular cAMP concentration. ...

Cyclic-di-GMP signaling is used by many bacteria to control biofilm formation. As biofilm formation is an important survival strategy for many bacteria, the synthesis and degradation of cyclic-di-GMP is tightly regulated by enzymes containing domains with conserved GGDEF and EAL sequence motifs, respectively. In this report we characterize a protein ...

Adenylation/adenylate-forming enzymes catalyze the activation of a carboxylic acid at the expense of ATP to form an acyl-adenylate intermediate and pyrophosphate (PP(i)). In a second half-reaction, adenylation enzymes catalyze the transfer of the acyl moiety of the acyl-adenylate onto an acceptor molecule, which can be either a protein or a ...

Cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate are ubiquitous calcium-mobilizing messengers produced by the same family of multifunctional enzymes, the ADP-ribosyl cyclases. Not all ADP-ribosyl cyclases have been identified, and how production of different messengers is achieved is incompletely understood. Here, we report the cloning and characterization of a ...