Backbone and side-chain 1H, 15N and 13C resonance assignments of S18Y mutant of ubiquitin carboxy-terminal hydrolase L1

Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), also known as PGP9.5, is a protein of 223 amino acids. Although it was originally characterized as a deubiquitinating enzyme, recent studies indicate that it also functions as a ubiquitin (Ub) ligase and a mono-Ub stabilizer. It is highly abundant in brain, constituting up to 2% of total brain proteins. Down-regulation and extensive oxidative modification of UCH-L1 have been observed in the brains of Alzheimer’s disease (AD) and Parkinson’s disease (PD) patients. Mutations in the UCH-L1 gene have been reported to be linked to Parkinson’s disease, in particular, the I93 M variant is associated with a higher susceptibility of PD in contrast to a higher protection against PD for the S18Y variant. Hence, the structure of UCH-L1 and the underlying effects of disease associated mutations on the structure and function of UCH-L1 are of considerable interest. Here, we report the NMR spectral assignments of the S18Y human UCH-L1 mutant with the aim to obtain better understanding about the risk of Parkinson’s disease against structural and dynamical changes induced by this mutation on UCH-L1

Examining consumers’ adoption of wearable healthcare technology: The role of health attributes

With the advancement of information technology, wearable healthcare technology has emerged as one of the promising technologies to improve the wellbeing of individuals. However, the adoption of wearable healthcare technology has lagged when compared to other well-established durable technology products, such as smartphones and tablets, because of the inadequate knowledge of the antecedents of adoption intention. The aim of this paper is to address an identified gap in the literature by empirically testing a theoretical model for examining the impact of consumers’ health beliefs, health information accuracy, and the privacy protection of wearable healthcare technology on perceived usefulness. Importantly, this study also examines the influences of perceived usefulness, consumer innovativeness, and reference group influence on the adoption intention of wearable healthcare technology. The model seeks to enhance understanding of the influential factors in adopting wearable healthcare technology. Finally, suggestions for future research for the empirical investigation of the model are provided

Soluble suppression of tumorigenicity 2 (sST2) for predicting disease severity or mortality outcomes in cardiovascular diseases: A systematic review and meta-analysis

Objectives: Soluble suppression of tumorigenicity 2 (sST2) is a member of the interleukin-1 receptor family. It is raised in various cardiovascular diseases, but its value in predicting disease severity or mortality outcomes has been controversial. Therefore, we conducted a systematic review and meta-analysis to determine whether sST2 levels differed between survivors and non-survivors of patients with cardiovascular diseases, and whether elevated sST2 levels correlated with adverse outcomes. Methods: PubMed and Embase were searched until 23rd June 2021 for studies that evaluated the relationship between sST2 levels and cardiovascular disease severity or mortality. Results: A total of 707 entries were retrieved from both databases, of which 14 studies were included in the final meta-analysis. In acute heart failure, sST2 levels did not differ between survivors and non-survivors (mean difference [MD]: 24.2 ± 13.0 ng/ml; P = 0.06; I2: 95%). Elevated sST2 levels tend to be associated with increased mortality risk (hazard ratio [HR]: 1.12, 95 %CI: 0.99–1.27, P = 0.07; I2: 88%). In chronic heart failure, sST2 levels were higher in non-survivors than in survivors (MD: 0.19 ± 0.04 ng/ml; P = 0.001; I2: 0%) and elevated levels were associated with increased mortality risk (HR: 1.64, 95% CI: 1.27–2.12, P < 0.001; I2: 82%). sST2 levels were significantly higher in severe disease compared to less severe disease (MD: 1.56 ± 0.46 ng/ml; P = 0.001; I2: 98%). Finally, in stable coronary artery disease, sST2 levels were higher in non-survivors than survivors (MD: 3.0 ± 1.1 ng/ml; P = 0.005; I2: 80%) and elevated levels were significantly associated with increased mortality risk (HR: 1.32, 95% CI: 1.04–1.68, P < 0.05; I2: 57%). Conclusions: sST2 significantly predicts disease severity and mortality in cardiovascular disease and is a good predictor of mortality in patients with stable coronary artery disease and chronic heart failure

Investigation of the impacts of Parkinson's-disease-associated mutations (193M and S18Y) on the structure of human ubiquitincarboxyl-terminal hydrolase L1

Ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), a protein of 223 amino acids, is a member of deubiquitinating enzymes and it is one of the most abundant proteins in the brain. Although the in vivo functions of UCH-L1 are still unclear, its abundance and specificity for neurons indicate that it may serve an important role in neuronal cell function or dysfunction. Indeed, an isoleucine 93 to methionine amino acid mutation (I93M) in UCH-L1 was identified to be linked to an autosomal dominant form of Parkinson’s disease, while the serine 18 to tyrosine amino acid mutation (S18Y) in UCH-L1 is linked to a decreased susceptibility to Parkinson’s disease. To investigate the effects of these mutations on the structure of human UCH-L1, the mutant proteins have been successfully over-expressed, biophysically characterized and compared with the wild-type UCH-L1 using circular dichroism and NMR spectroscopy. While the data from circular dichroism and NMR chemical shift perturbation analysis suggested that the S18Y point mutation only slightly perturbs the global structure, the effect of the I93M point mutation was found to be more profound. In particular, the structural perturbations caused by I93M substitution are not only observed near the site of mutation, but are also found at more distant sites. These structural perturbations may be significant for the function of UCH-L1 and explain the reduced hydrolase activity (~55 % of wild-type) observed in UCH-L1-I93M, as the geometry of the catalytic triad (C90, H161 and D176) is likely to be distorted by this substitution. To provide further insights into the effect of serine 18 to tyrosine (S18Y) mutation on the structure and function of UCH-L1, the three-dimensional solution structure of UCH-L1-S18Y was determined by NMR spectroscopy. The solution structure of UCH-L1-S18Y reveals a monomer with a typical fold of papain-like cysteine proteases and consists of a six-membered antiparallel β-sheet surrounded by eight α-helices. Although the global structure is very similar to the crystal structure of wild-type UCH-L1, both the altered hydrogen bond network and the surface charge distributions have demonstrated that the S18Y substitution could lead to profound structural changes. In particular, the analysis of the difference in the dimeric interfaces of the wild-type and the S18Y mutant showed that the serine to tyrosine mutation can significantly affect the distribution of the surface-exposed residues involved in the dimeric interface. It is thought that such observed differences might weaken the stability of the UCH-L1 dimer and hence may explain the reduced dimerization-dependent ligase activity of UCH-L1-S18Y in comparison to the wild-type UCH-L1.published_or_final_versionChemistryDoctoralDoctor of Philosoph

Dynamic Nuclear Polarization: New Methodology and Applications

One way to overcome the intrinsically low sensitivity of Nuclear Magnetic Resonance spectroscopy is to enhance the signal by dynamic nuclear polarization (DNP), where the polarization of high-gyromagnetic ratio (gamma) electrons is transferred to the surrounding nuclei using microwave (MW) irradiation. Recent developments in DNP instrumentations and applications have shown that DNP is one of the most effective methods to increase the nuclear spin polarization in inorganic, organic, and biological materials. It is possible to obtain a solution of molecules containing hyperpolarized nuclei in combination with methods to dissolve rapidly the polarized solid sample. In this chapter, a brief introduction on a theoretical basis and some of new DNP applications in NMR spectroscopy as well as medical applications in Magnetic Resonance Imaging (MRI) are described

Uncovering insights from healthcare archives to improve operations: An association analysis for cervical cancer screening

The digitalisation in healthcare opens opportunities for more effective chronic disease management. Digitalised medical records are valuable data sources for identifying high-risk patients and facilitating early clinical intervention. However, the liberation of data has plagued adoption amongst physicians as massive data mean more difficult to identify important knowledge from the data. In the cervical cancer context, many patients are adherence to prescription medications only when symptoms appear, beyond the earlier point-in-time of the disease progression. Regular screening is the only way to detect abnormal cells that may develop into cancer if left untreated. Yet, without a comprehensive understanding of the relationship between risk factors and healthcare outcomes, inappropriate screening procedures may be conducted, lengthening the treatment process. Delay in the treatment process may have an irreversible influence on patients’ conditions as chronic diseases progress. This study demonstrates a data-mining framework which extracts knowledge that can advance cervical cancer screening processes in the form of association rules and improves the generalisation potential of the rules for deployment. The knowledge discovered serves as an additional supplement for physicians’ experience and uncovers appropriate screening strategies based on patients’ risk factors, increasing the chances of high-risk patients getting treated for cervical pre-cancers

Detection of Intrahepatic Hepatitis B Virus DNA and Correlation with Hepatic Necroinflammation and Fibrosis

Assessment of intrahepatic hepatitis B virus (HBV) DNA levels in patients with chronic hepatitis B is important in understanding the natural history of the disease and designing antiviral therapy regimens. However, there is no standardized method for the measurement of intrahepatic HBV DNA levels. We describe a convenient novel method for the measurement of intrahepatic HBV DNA levels based on a modified COBAS Amplicor HBV Monitor test for HBV DNA measurement and real-time PCR β-actin gene detection for human genomic DNA (hgDNA) quantitation. Fifteen hepatitis B e antigen (HBeAg)-positive patients, 26 patients positive for antibody to HBeAg (anti-HBe), and 8 control patients were recruited. The mean between-run coefficient of variation for the β-actin real-time PCR assay was 15.4%. All eight control patients had undetectable intrahepatic and serum HBV DNA levels. All chronic hepatitis B patients had detectable intrahepatic HBV DNA levels, and all but one anti-HBe-positive patient had detectable serum HBV DNA levels. HBeAg-positive patients had higher median intrahepatic and serum HBV DNA levels than anti-HBe-positive patients (6,950 versus 676 HBV DNA copies/ng of hgDNA, respectively [P < 0.001] and 184 × 10(6) versus 6.65 × 10(6) copies/ml, respectively [P < 0.001]). The intrahepatic HBV DNA levels correlated strongly with the serum HBV DNA levels (r = 0.842; P < 0.001) and with the degree of fibrosis (P = 0.014). We conclude that the method that we describe is reliable and convenient for the measurement of intrahepatic HBV DNA levels and has potential clinical significance