scholarly journals Neurolectins: Biochemical Characterisation and Functions

2017 ◽  
Vol 3 (2) ◽  
pp. 338-348
Author(s):  
Nugzar Aleksidze ◽  
Keyword(s):  
Biochemical Characterisation

Biochemical Characterisation of Elite Green Gram (Vigna Radiata (L.)Wilczek) Genotypes

2012 ◽  
Vol 3 (3) ◽  
pp. 1-2
Author(s):  
Lavanya. S * Anandhi ◽  
◽  
Vanniarajan. C Vanniarajan. C
Keyword(s):  
Vigna Radiata ◽  
Green Gram ◽  
Biochemical Characterisation

scholarly journals Disulfide bond engineering of AppA phytase for increased thermostability requires co-expression of protein disulfide isomerase in Pichia pastoris

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Laura Navone ◽  
Thomas Vogl ◽  
Pawarisa Luangthongkam ◽  
Jo-Anne Blinco ◽  
Carlos H. Luna-Flores ◽  
...  
Keyword(s):  
Pichia Pastoris ◽  
Phytic Acid ◽  
Disulfide Bond ◽  
Wild Type ◽  
Wild Type Enzyme ◽  
E Coli ◽  
Biochemical Characterisation ◽  
Disulfide Bond Isomerase ◽  
Microbial Systems ◽  
Protein Disulfide

Abstract Background Phytases are widely used commercially as dietary supplements for swine and poultry to increase the digestibility of phytic acid. Enzyme development has focused on increasing thermostability to withstand the high temperatures during industrial steam pelleting. Increasing thermostability often reduces activity at gut temperatures and there remains a demand for improved phyases for a growing market. Results In this work, we present a thermostable variant of the E. coli AppA phytase, ApV1, that contains an extra non-consecutive disulfide bond. Detailed biochemical characterisation of ApV1 showed similar activity to the wild type, with no statistical differences in kcat and KM for phytic acid or in the pH and temperature activity optima. Yet, it retained approximately 50% activity after incubations for 20 min at 65, 75 and 85 °C compared to almost full inactivation of the wild-type enzyme. Production of ApV1 in Pichia pastoris (Komagataella phaffi) was much lower than the wild-type enzyme due to the presence of the extra non-consecutive disulfide bond. Production bottlenecks were explored using bidirectional promoters for co-expression of folding chaperones. Co-expression of protein disulfide bond isomerase (Pdi) increased production of ApV1 by ~ 12-fold compared to expression without this folding catalyst and restored yields to similar levels seen with the wild-type enzyme. Conclusions Overall, the results show that protein engineering for enhanced enzymatic properties like thermostability may result in folding complexity and decreased production in microbial systems. Hence parallel development of improved production strains is imperative to achieve the desirable levels of recombinant protein for industrial processes.

scholarly journals Differential Exoproteome and Biochemical Characterisation of Neoparamoeba perurans

2021 ◽  
Vol 9 (6) ◽  
pp. 1258
Author(s):  
Kerrie Ní Ní Dhufaigh ◽  
Natasha Botwright ◽  
Eugene Dillon ◽  
Ian O’Connor ◽  
Eugene MacCarthy ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Virulence Factors ◽  
Cytotoxic Effect ◽  
Differentially Expressed Proteins ◽  
Biochemical Characterisation ◽  
Key Players ◽  
Prolonged Culture ◽  
Global Threat ◽  
Iron Receptor ◽  
Trout Gill

Infection with the protozoan ectoparasite Neoparamoeba perurans, the causative agent of AGD, remains a global threat to salmonid farming. This study aimed to analyse the exoproteome of both an attenuated and virulent N. perurans isolate using proteomics and cytotoxicity testing. A disproportionate presence of proteins from the co-cultured microbiota of N. perurans was revealed on searching an amalgamated database of bacterial, N. perurans and Amoebozoa proteins. LC‑MS/MS identified 33 differentially expressed proteins, the majority of which were upregulated in the attenuated exoproteome. Proteins of putative interest found in both exoproteomes were maltoporin, ferrichrome-iron receptor, and putative ferric enterobactin receptor. Protease activity remained significantly elevated in the attenuated exoproteome compared with the virulent exoproteome. Similarly, the attenuated exoproteome had a significantly higher cytotoxic effect on rainbow trout gill cell line (RTgill W1) cells compared with the virulent exoproteome. The presence of a phosphatase and serine protease in the virulent exoproteome may facilitate AGD infection but do not appear to be key players in causing cytotoxicity. Altogether, this study reveals prolonged culture of N. perurans affects the exoproteome composition in favour of nutritional acquisition, and that the current culturing protocol for virulent N. perurans does not facilitate the secretion of virulence factors.

scholarly journals Isolation and characterization of two virulent Aeromonads associated with haemorrhagic septicaemia and tail-rot disease in farmed climbing perch Anabas testudineus

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abhishek Mazumder ◽  
Hrishikesh Choudhury ◽  
Abhinit Dey ◽  
Dandadhar Sarma
Keyword(s):  
Natural Infection ◽  
Winter Season ◽  
Pcr Amplification ◽  
Body Parts ◽  
Anabas Testudineus ◽  
Climbing Perch ◽  
Isolation And Characterization ◽  
Biochemical Characterisation ◽  
Rot Disease

AbstractDiseased Anabas testudineus exhibiting signs of tail-rot and ulcerations on body were collected from a fish farm in Assam, India during the winter season (November 2018 to January 2019). Swabs from the infected body parts were streaked on sterilized nutrient agar. Two dominant bacterial colonies were obtained, which were then isolated and labelled as AM-31 and AM-05. Standard biochemical characterisation and 16S rRNA and rpoB gene sequencing identified AM-31 isolate as Aeromonas hydrophila and AM-05 as Aeromonas jandaei. Symptoms similar to that of natural infection were observed on re-infecting both bacteria to disease-free A. testudineus, which confirmed their virulence. LC50 was determined at 1.3 × 104 (A. hydrophila) and 2.5 × 104 (A. jandaei) CFU per fish in intraperitoneal injection. Further, PCR amplification of specific genes responsible for virulence (aerolysin and enterotoxin) confirmed pathogenicity of both bacteria. Histopathology of kidney and liver in the experimentally-infected fishes revealed haemorrhage, tubular degeneration and vacuolation. Antibiotic profiles were also assessed for both bacteria. To the best of our knowledge, the present work is a first report on the mortality of farmed climbing perch naturally-infected by A. hydrophila as well as A. jandaei, with no records of pathogenicity of the latter in this fish.

scholarly journals Rab1-AMPylation by Legionella DrrA is allosterically activated by Rab1

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jiqing Du ◽  
Marie-Kristin von Wrisberg ◽  
Burak Gulen ◽  
Matthias Stahl ◽  
Christian Pett ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Adenosine Monophosphate ◽  
Vesicular Trafficking ◽  
Bacterial Protein ◽  
Post Translational Modification ◽  
Allosteric Control ◽  
Rab Protein ◽  
Biochemical Characterisation ◽  
A Site ◽  
Insight Into

AbstractLegionella pneumophila infects eukaryotic cells by forming a replicative organelle – the Legionella containing vacuole. During this process, the bacterial protein DrrA/SidM is secreted and manipulates the activity and post-translational modification (PTM) states of the vesicular trafficking regulator Rab1. As a result, Rab1 is modified with an adenosine monophosphate (AMP), and this process is referred to as AMPylation. Here, we use a chemical approach to stabilise low-affinity Rab:DrrA complexes in a site-specific manner to gain insight into the molecular basis of the interaction between the Rab protein and the AMPylation domain of DrrA. The crystal structure of the Rab:DrrA complex reveals a previously unknown non-conventional Rab-binding site (NC-RBS). Biochemical characterisation demonstrates allosteric stimulation of the AMPylation activity of DrrA via Rab binding to the NC-RBS. We speculate that allosteric control of DrrA could in principle prevent random and potentially cytotoxic AMPylation in the host, thereby perhaps ensuring efficient infection by Legionella.

Biochemical characterisation of an apparently novel isoform of protein kinase C in pituitary

1993 ◽  
Vol 21 (4) ◽  
pp. 386S-386S ◽  
Author(s):  
ANGELA J. ISON ◽  
MELANIE S. JOHNSON ◽  
DAVID J. MacEWAN ◽  
JAMES SIMPSON ◽  
ROGER A. CLEGG ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Kinase C ◽  
Biochemical Characterisation

Biochemical characterisation of an auxotroph of Datura Innoxia requiring isoleucine and valine

Plant Science ◽  
1986 ◽  
Vol 43 (2) ◽  
pp. 109-114 ◽  
Author(s):  
Roger M. Wallsgrove ◽  
Ruth Risiott ◽  
John King ◽  
Simon W.J. Bright
Keyword(s):  
Datura Innoxia ◽  
Biochemical Characterisation
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