Hydrophobic substrate binding pocket remodeling of echinocandin B deacylase based on multi-dimensional rational design.

Actinoplanes utahensis deacylase (AAC)-catalyzed deacylation of echinocandin B (ECB) is a promising method for the synthesis of anidulafungin, the newest of the echinocandin antifungal agents. However, the low activity of AAC significantly limits its practical application. In this work, we have devised a multi-dimensional rational design strategy for AAC, conducting separate analyses on the substrate-binding pocket's volume, curvature, and length. Furthermore, we quantitatively analyzed substrate properties, particularly on hydrophilic and hydrophobic. Accordingly, we tailored the linoleic acid-binding pocket of AAC to accommodate the extended long lipid chain of ECB. By fine-tuning the key residues, the resulting AAC mutants can accommodate the ECB lipid chain with a lower curvature binding pocket. The D53A/I55F/G57M/F154L/Q661L mutant (MT) displayed 331 % higher catalytic efficiency than the wild-type (WT) enzyme. The MT product conversion was 94.6 %, reaching the highest reported level. Utilizing a multi-dimensional rational design for a customized mutation strategy of the substrate-binding pocket is an effective approach to enhance the catalytic efficiency of enzymes in handling complicated substrates.

Awareness of HPV and HPV vaccines, acceptance to vaccination and its influence factors among parents of adolescents 9 to 18 years of age in China: A cross-sectional study.

BACKGROUND: Vaccination uptake rates for adolescents are still low in China despite safe and effective human papillomavirus vaccines being available. The awareness and attitudes of parents to HPV vaccines play a decisive role in adolescents' HPV vaccination uptake. METHODS: A cross-sectional study was conducted from March, 2022 to May, 2022 using an anonymous questionnaire among parents of 9 to 18 years of age from 73 cities in 23 provinces in mainland China. Demographic characteristics of parents, their knowledge and attitudes about HPV and HPV vaccination, as well as factors influencing HPV vaccination in adolescents were assessed. RESULTS: More than two-thirds of parents heard of HPV (75.5%) and HPV vaccines (84.7%). Of these participants, mothers (83.8%) were in the majority. Parents willing to vaccinate themselves and their children against HPV were 84.9% and 87.6%, respectively. Parents were more likely to vaccinate their daughters against HPV than their sons (P < 0.001). Parents who had heard of the HPV vaccines (P = 0.028) or had vaccinated themselves (P < 0.001) were more likely to have HPV vaccination for their children. Parents who accepted the price of the HPV vaccines (P = 0.005) were more likely to have their children vaccinated against HPV. CONCLUSIONS: Children's gender, awareness of the HPV vaccines, parental HPV vaccination, and the price of the HPV vaccines are likely to be the reason for parents' vaccine hesitancy for adolescents. PRACTICE IMPLICATIONS: Nurses have a critical role in identifying parental hesitancy and providing individualized education to expand the parental awareness and knowledge and encourage on-time adolescents vaccination.

Functional expression of an echinocandin B deacylase from Actinoplanes utahensis in Escherichia coli.

Echinocandin B deacylase (ECBD) from Actinoplanes utahensis can be applied to produce echinocandin B nucleus (ECBN), an essential intermediate of the echinocandins antifungal drugs such as anidulafungin. To date, the expression of ECBD has been limited to Streptomyces. To achieve the active expression of ECBD in Escherichia coli (E. coli), we constructed a plasmid carrying two subunits of ECBD for T7 RNA polymerase driven transcription of dicistron messenger after codon optimization. Subsequently, the introduction of peptide tags in the recombinant ECBD was adopted to reduce the formation of inclusion bodies and enhance the ECBD solubility. The peptide tags with the opposite electrostatic charge, hexa-lysine (6K) and GEGEG (GE), exhibited the best positive effect, which was verified by activity assay and structural simulation. After that, optimization of culture conditions and characterization of ECBD were conducted, the optimal pH and temperature were 7.0 and 60 °C. It is the first report concerning the functional expression of ECBD in the host E. coli. Our results reported here can provide a reference for the high-level expression of other deacylases with respect to a possible industrial application.

Effect of pre-emptive analgesia by continuous femoral nerve block on early postoperative cognitive function following total knee arthroplasty in elderly patients.

To the best of our knowledge, the effect of pre-emptively blocking pain transmission on acute postoperative cognitive dysfunction (POCD) has not yet been assessed. Therefore, the present study aimed to investigate the effect of pre-emptive analgesia via a continuous femoral nerve block (CFNB) on postoperative pain and early cognitive function following total knee arthroplasty (TKA) surgery in elderly patients. CFNB was performed prior to TKA surgery in the pre-emptive analgesia group (n=30) and following TKA surgery in the control group (n=30). POCD was defined as a two-point reduction in the postoperative score compared with the preoperative score in the mini-mental state examination. The visual analog scale (VAS) was used to evaluate the intensity of pain at rest and during exercise. The intraoperative dose of remifentanil in the pre-emptive analgesia group was significantly lower than in the control group (P<0.01). In the preemptive analgesia group, VAS scores at three days post-surgery were lower than those in the control group (P<0.01). The incidence of POCD on the third postoperative day was slightly lower in the pre-emptive analgesia group compared with the control group. In conclusion, the results demonstrate that pre-emptive analgesia by CFNB may promote the recovery of early cognitive function following TKA in elderly patients.