optimization-antigen-preparation-for-hemagglutination-inhibition

Optimization of Antigen Preparation for Hemagglutination Inhibition Assay of Newcastle Disease Virus Serology

Accurate assessment of Newcastle disease virus (NDV) antibody titers is crucial for effective poultry disease control and surveillance. This article ...

Suzhou Chien-shiung Institute of Technology

In this study, a GH78 α-L-rhamnosidase AtRha from Aspergillus terreus CCF3059 was screened and expressed in Pichia pastoris KM71H. The maximum enzyme activity of AtRha was 1000 U/mL after 12 days. AtRha was most active at 65 °C and pH 6.5, displaying excellent thermal stability and pH stability. The kinetic parameters Km, Vmax, kcat and kcat/Km values for pNPR were 0.481 mM, 659 μmol/min·mg, 1065 s-1 and 2214 s-1mM-1, respectively. AtRha could be inhibited by Fe2+, Hg2+ and Cu2+. Moreover, it displayed good tolerance to organic reagents with 52.6% activity in 15%(w/v) methanol. AtRha can hydrolyze icariin containing the α-1 rhamnoside linkage. Furthermore, AtRha and β-glucosidase TthBg3 showed excellent selectivity to cleave the rhamnose at the 3rd position and the glucosyl at the C-7 group of icariin, which established an effective and green method to produce the more pharmacological active icaritin. In addition, the optimal enzyme addition schemes and the reaction conditions were screened and optimized. After a two-stage transformation under optimized conditions, 0.5 g/L of icariin was transformed into 0.25 g/L of icaritin, with a corresponding molar conversion rate of 91.2%. Our findings provide a new, specific and cost-effective method for the production of icaritin in the industry.

Screening and characterization of a GH78 α-l-rhamnosidase from Aspergillus terreus and its application in the bioconversion of icariin to icaritin with recombinant β-glucosidase.

An α-L-rhamnosidase gene from .  subsp.  DSM 2910 (TstRhaA) was cloned and expressed. The maximum TstRhaA activity of the protein reached 25.2 U/ml, and the molecular mass was approximately 106.6 kDa. The protein was purified 8.0-fold by Ni-TED affinity with an overall recovery of 16.6% and a specific activity of 187.9 U/mg. TstRhaA activity was the highest at 65°C and pH 6.5. In addition, it exhibited excellent thermal stability, better pH stability, good tolerance to low concentrations of organic reagents, and high catalytic activity for -nitrophenyl-α-L-rhamnopyranoside (NPR). Substrate specificity studies showed that TstRhaA exhibited a high specific activity for rutin. At 60°C, pH 6.5, and 0.3 U/ml enzyme dosage, 60 g/l rutin was converted to 45.55 g/l isoquercitrin within 150 min. The molar conversion rate of rutin and the yield of isoquercitrin were 99.8% and 12.22 g/l/h, respectively. The results suggested that TstRhaA could be used for mass production of isoquercitrin.

Heterologous Expression and Characterization of a Thermostable α-L-Rhamnosidase from  subsp.  DSM 2910 and Its Application in the Biotransformation of Rutin.

Canine enteric coronavirus (CECoV) is a prevalent infectious disease among dogs worldwide, yet its epidemiology in mainland China remains poorly understood. This systematic review and meta-analysis aimed to assess the prevalence of CECoV in mainland China and identify factors influencing its prevalence.

A systematic review and meta-analysis of canine enteric coronavirus prevalence in dogs of mainland China.

Gastrodin is the main bioactive component of , which has many excellent pharmacological activities. In this study, UDP-glycosyltransferase from  (SlyUGT) was overexpressed, purified and characterized, and it can be used for biosynthesis of gastrodin. The SlyUGT maximum enzyme activity was 29.48 mU/ml, and its relative molecular weight was about 78.5 kDa. The SlyUGT was purified 16.1-fold by GST affinity resin with an overall recovery of 53.9% and specific activity of 20.9 mU/mg. The optimal temperature of SlyUGT was 40°C, and it exhibited excellent thermal stability at 35°C and 40°C. Furthermore, the SlyUGT had the highest activity at pH 9.5 and good pH stability at pH 5.5-10.5. The enzyme can tolerate low concentrations of DMSO and UDP. In addition, the values of  and  were found to be 0.65 mM and 74.60 mU/mg respectively. The SlyUGT could convert HBA into gastrodin by using UDP-glucose as a sugar donor. Under the optimal biosynthesis conditions, the gastrodin production reached 559.83 mg/l, and the corresponding molar conversion rate reached 97.82%. The results showed that SlyUGT has potential application value in the preparation of gastrodin.

Article	Year
Screening and characterization of a GH78 α-l-rhamnosidase from Aspergillus terreus and its application in the bioconversion of icariin to icaritin with recombinant β-glucosidase. Enzyme and microbial technology\| PubMed ID: 34781207	2022
Heterologous Expression and Characterization of a Thermostable α-L-Rhamnosidase from subsp. DSM 2910 and Its Application in the Biotransformation of Rutin. Journal of microbiology and biotechnology\| PubMed ID: 37644729	2023
A systematic review and meta-analysis of canine enteric coronavirus prevalence in dogs of mainland China. Virology journal\| PubMed ID: 38982509	2024
Recombinant Expression and Characterization of an Alkali-tolerant UDP-Glycosyltransferase from and Its Biosynthesis of Gastrodin. Journal of microbiology and biotechnology\| PubMed ID: 39682001	2024

Lin Ge

Biography

JoVE Journal Publications

Other Publications