scholarly journals Secreted lipases from Malassezia globosa: recombinant expression and determination of their substrate specificities

Microbiology ◽  
2016 ◽  
Vol 162 (7) ◽  
pp. 1069-1079 ◽  
Author(s):  
Bettina Sommer ◽  
David P. Overy ◽  
Bradley Haltli ◽  
Russell G. Kerr
Keyword(s):  
Recombinant Expression ◽  
Substrate Specificities ◽  
Malassezia Globosa

scholarly journals A rapid direct assay for the determination of the separate activities of the three arylsulphatases of Aspergillus oryzae

1977 ◽  
Vol 166 (3) ◽  
pp. 411-413 ◽  
Author(s):  
G R J Burns ◽  
C H Wynn
Keyword(s):  
Phenolic Compounds ◽  
Aspergillus Oryzae ◽  
Substrate Specificities ◽  
Direct Assay ◽  
Assay Procedure ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Potential Use

1. The three arylsulphatases of Aspergillus oryzae exhibit pronounced kinetic differences and substrate specificities. Arylsulphatase I hydrolyses all substrates tested, whereas arylsulphatase III will not hydrolyse tyrosine O-sulphate or phenolphthalein disulphate. Arylsulphatase II does not hydrolyse p-nitrophenyl sulphate or phenolphthalein disulphate at appreciable rates in the absence of added phenolic compounds. Phenols such as tyramine increase the rate of hydrolysis of these substances by this enzyme 1000-fold. At pH 6.9 arylsulphatase I exhibits an apparent Km of 0.1 mM for p-nitrophenyl sulphate, whereas the Km of arylsulphatase III for this substrate is 1 mM. 2. These differences were utilized to develop an assay procedure which can be used to determine the separate activities of the three enzymes present in mixtures. This assay has potential use as a means of examining the relative activities of the three enzymes in investigations of the differences in the mechanisms regulating their synthesis.

A high-throughput and generic assay method for the determination of substrate specificities of thermophilic α-aminotransferases

2007 ◽  
Vol 71 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Toshiya Sawai ◽  
Daisuke Koma ◽  
Ryotaro Hara ◽  
Kuniki Kino ◽  
Shigeaki Harayama
Keyword(s):  
High Throughput ◽  
Assay Method ◽  
Substrate Specificities

scholarly journals Functional Analysis of Two l-Arabinose Transporters from Filamentous Fungi Reveals Promising Characteristics for Improved Pentose Utilization in Saccharomyces cerevisiae

2015 ◽  
Vol 81 (12) ◽  
pp. 4062-4070 ◽  
Author(s):  
Jingen Li ◽  
Jing Xu ◽  
Pengli Cai ◽  
Bang Wang ◽  
Yanhe Ma ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sugar Transport ◽  
Biomass Accumulation ◽  
Kinetic Properties ◽  
High Identity ◽  
Content Type ◽  
Substrate Specificities ◽  
Dry Cell Weight ◽  
Dry Cell

ABSTRACTLimited uptake is one of the bottlenecks forl-arabinose fermentation from lignocellulosic hydrolysates in engineeredSaccharomyces cerevisiae. This study characterized two novell-arabinose transporters, LAT-1 fromNeurospora crassaand MtLAT-1 fromMyceliophthora thermophila. Although the two proteins share high identity (about 83%), they display different substrate specificities. Sugar transport assays using theS. cerevisiaestrain EBY.VW4000 indicated that LAT-1 accepts a broad substrate spectrum. In contrast, MtLAT-1 appeared much more specific forl-arabinose. Determination of the kinetic properties of both transporters revealed that theKmvalues of LAT-1 and MtLAT-1 forl-arabinose were 58.12 ± 4.06 mM and 29.39 ± 3.60 mM, respectively, with correspondingVmaxvalues of 116.7 ± 3.0 mmol/h/g dry cell weight (DCW) and 10.29 ± 0.35 mmol/h/g DCW, respectively. In addition, both transporters were found to use a proton-coupled symport mechanism and showed only partial inhibition byd-glucose duringl-arabinose uptake. Moreover, LAT-1 and MtLAT-1 were expressed in theS. cerevisiaestrain BSW2AP containing anl-arabinose metabolic pathway. Both recombinant strains exhibited much fasterl-arabinose utilization, greater biomass accumulation, and higher ethanol production than the control strain. In conclusion, because of higher maximum velocities and reduced inhibition byd-glucose, the genes for the two characterized transporters are promising targets for improvedl-arabinose utilization and fermentation inS. cerevisiae.

Determination of the Substrate Specificities ofN-Acetyl-d-glucosaminyltransferase†

Biochemistry ◽  
2006 ◽  
Vol 45 (40) ◽  
pp. 12358-12365 ◽  
Author(s):  
Miao Chen ◽  
Arlene Bridges ◽  
Jian Liu
Keyword(s):  
Substrate Specificities

scholarly journals Conservation of substrate specificities among coronavirus main proteases

2002 ◽  
Vol 83 (3) ◽  
pp. 595-599 ◽  
Author(s):  
Annette Hegyi ◽  
John Ziebuhr
Keyword(s):  
Hepatitis Virus ◽  
Relative Rate ◽  
Transmissible Gastroenteritis Virus ◽  
Substrate Specificities ◽  
Infectious Bronchitis ◽  
Main Protease ◽  
Key Enzyme ◽  
Relative Rate Constants ◽  
Transmissible Gastroenteritis

The key enzyme in coronavirus replicase polyprotein processing is the coronavirus main protease, 3CLpro. The substrate specificities of five coronavirus main proteases, including the prototypic enzymes from the coronavirus groups I, II and III, were characterized. Recombinant main proteases of human coronavirus (HCoV), transmissible gastroenteritis virus (TGEV), feline infectious peritonitis virus, avian infectious bronchitis virus and mouse hepatitis virus (MHV) were tested in peptide-based trans-cleavage assays. The determination of relative rate constants for a set of corresponding HCoV, TGEV and MHV 3CLpro cleavage sites revealed a conserved ranking of these sites. Furthermore, a synthetic peptide representing the N-terminal HCoV 3CLpro cleavage site was shown to be effectively hydrolysed by noncognate main proteases. The data show that the differential cleavage kinetics of sites within pp1a/pp1ab are a conserved feature of coronavirus main proteases and lead us to predict similar processing kinetics for the replicase polyproteins of all coronaviruses.

Determination of Substrate Specificities Against ��-Glucosidase A (BglA) from Thermotoga maritime: A Molecular Docking Approach

2015 ◽  
Vol 25 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Muhammad Ibrahim Rajoka ◽  
Sobia Idrees ◽  
Usman Ali Ashfaq ◽  
Beenish Ehsan ◽  
Asma Haq
Keyword(s):  
Molecular Docking ◽  
Substrate Specificities ◽  
Docking Approach

Prevalence of FACTOR IX-R338L (FACTOR IX PADUA) IN A COHORT of PATIENTS with Venous Thromboembolism and Mild Elevation of FACTOR IX LEVELS.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 5057-5057
Author(s):  
Bruna de Moraes Mazetto ◽  
Fernanda A. Orsi ◽  
Lúcia Helena Siqueira ◽  
Erich Vinicius de Paula ◽  
Tayana B Mello ◽  
...  
Keyword(s):  
Venous Thromboembolism ◽  
Molecular Mechanisms ◽  
Conflicts Of Interest ◽  
Recombinant Expression ◽  
Coagulation Factor ◽  
Factor Ix ◽  
Control Group ◽  
Increased Risk ◽  
Pcr Rflp

Abstract Abstract 5057 Introduction Elevated plasma levels of blood coagulation factor IX (FIX) have been associated with increased risk of venous thromboembolism (VTE) in humans. However, the molecular mechanisms underlying elevated FIX have not been elucidated. Recently, a mutation in the FIX gene resulting in a FIX molecule with Arginine Leucine substitution at position 338 (FIX-R338L or Factor IX Padua) has been associated with very high levels of FIX (776%) in a patient with spontaneous VTE. Recombinant expression of FIX-R338L confirmed the gain-of-function mutation. Objective Here we evaluated the levels of FIX and the prevalence of Factor IX Padua in a cohort of patients with VTE followed at our center. The prevalence of FIX Padua was evaluated by using a PCR-RFLP strategy by which PCR with specific primers was followed by digestion with the enzyme TaqI. Results The prevalence of FIX Padua was evaluated in a population of 192 patients with spontaneous VTE (69 males and 123 females; median age 36-yo). A population of 192 healthy individuals matched for age, sex and ethnicity was used as a control group for the determination of FIX levels. Median FIX levels was 128.0% (61.0-207.0%) in patients with VTE. Twenty-nine patients presented FIX levels above the 90th percentile (160.2%). Factor IX Padua was not identified in any patients or controls, even in those with elevated FIX levels. Conclusion in the present study FIX Padua was not identified in any of our patients, indicating that this mutation is not associated with mild elevations of FIX levels frequently observed in patients with VTE. Disclosures No relevant conflicts of interest to declare.

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