Disaggregation of amyloid-like protein aggregates isolated from human cataract lens

Crystallins, which represents the major lens protein, play a significant role in ensuring the lens transparency and maintenance of appropriate refractive index of the lens that help in accurate focusing of incident visible light precisely on retina to create clear image perception. Aggregation of lens proteins is known to form the basis of cataract formation. The present study is an attempt to examine the stability of the lens protein aggregates, isolated from human cataract eye lens, against an anionic detergent Sodium dodecyl sulphate (SDS), which is known to disrupt the hydrophobic interaction of protein aggregates. Data that emerged from Congo red (CR), thioflavin T (ThT) and 8-anilino-1-naphthalene sulfonic acid (ANS) binding assaysindicated their amyloidogenic nature. A significant reduction in the bathochromic shift of CR λmax and ThT fluorescence emission intensity were observed after treatment of the aggregated proteins with SDS. In the presence of SDS, a significant change in the number and size of the protein aggregates were observed during their morphological analyses under transmission electron microscopy (TEM). Based on the above data it became evident that the hydrophobic interaction plays a crucial role in formation and stabilizing the protein aggregates during cataract formation

Thermal stability of α-amylase in aqueous cosolvent systems

The activity and thermal stability of α-amylase were studied in the presence of different concentrations of trehalose, sorbitol, sucrose and glycerol. The optimum temperature of the enzyme was found to be 50 ± 2°C. Further increase in temperature resulted in irreversible thermal inactivation of the enzyme. In the presence of cosolvents, the rate of thermal inactivation was found to be significantly reduced. The apparent thermal denaturation temperature (T m)app and activation energy (E a ) of α-amylase were found to be significantly increased in the presence of cosolvents in a concentration-dependent manner. In the presence of 40% trehalose, sorbitol, sucrose and glycerol, increments in the (T m)app were 20°C, 14°C, 13°C and 9°C, respectively. The E a of thermal denaturation of α-amylase in the presence of 20% (w/v) trehalose, sorbitol, sucrose and glycerol was found to be 126, 95, 90 and 43 kcal/mol compared with a control value of 40 kcal/mol. Intrinsic and 8-anilinonaphathalene-1-sulphonic acid (ANS) fluorescence studies indicated that thermal denaturation of the enzyme was accompanied by exposure of the hydrophobic cluster on the protein surface. Preferential interaction parameters indicated extensive hydration of the enzyme in the presence of cosolvents

Correlation of hs-CRP with environmental risk factors of nephropathy in type 2 diabetes

The objective of the present study was to investigate the association of hs-CRP levels with environmental risk factors of diabetic nephropathy like smoking, drinking alcohol, diet, age of diabetic patient, duration of diabetes, medication of diabetes, and blood pressure medication. A hospital-based quantitative study was conducted at the Department of Clinical Biochemistry of Manipal Teaching Hospital (MTH) Pokhara, Nepal, with 89 patients suffering from type 2 diabetes. Blood samples (n=89) from the patients were collected and the serums were separated. On the other hand, data on environmental risk factors of nephropathy were collected by using standard questionnaire. In this study, serum hs-CRP level was not found to be correlated with smoking (p=0.111), alcohol consumption (p=0.722), diet (p=0.496), duration of diabetes (p=0.519), age of diabetic patient (p=0.369), medication of diabetes (p=0.734), and blood pressure medication (p=0.625). Hence, our study concludes that serum hs-CRP value in type 2 diabetic patients is insignificantly correlated with the risk factors especially smoking, drinking alcohol, diet, duration of diabetes, age of diabetic patient, medication of diabetes, and medication of blood pressure

Structure, function and antagonism of semen amyloids

Amyloid fibrils are linear polypeptide aggregates with a cross-β structure. These fibrils are best known for their association with neurodegenerative diseases, such as Alzheimer's or Parkinson's, but they may also be used by living organisms as functional units, e.g. in the synthesis of melanin or in the formation of bacterial biofilms. About a decade ago, in a search for semen factors that modulate infection by HIV-1 (a sexually transmitted virus and the causative agent of the acquired immune deficiency syndrome (AIDS)), it was demonstrated that semen harbors amyloid fibrils capable of markedly increasing HIV infection rates. This discovery not only created novel opportunities to prevent sexual HIV-1 transmission but also stimulated research to unravel the natural role of these factors. We discuss here the identification of these intriguing structures, their molecular properties, and their effects on both sexually transmitted diseases and reproductive health. Moreover, we review strategies to antagonize semen amyloid to prevent sexual transmission of viruses

Sexually Transmitted Infections and Behavioral Determinants of Sexual and Reproductive Health in the Allahabad District (India) Based on Data from the ChlamIndia Study

Background: Sexually transmitted infections (STIs), like Chlamydia trachomatis and Neisseria gonorrhoeae (CT and NG, respectively) are linked to an important sexual and reproductive health (SRH) burden worldwide. Behavior is an important predictor for SRH, as it dictates the risk for STIs. Assessing the behavior of a population helps to assess its risk profile. Methods: Study participants were recruited at a gynecology outpatient department (OPD) in the Allahabad district in Uttar Pradesh India, and a questionnaire was used to assess demographics, SRH, and obstetric history. Patients provided three samples (urine, vaginal swab, and whole blood). These samples were used to identify CT and NG using PCR/NAAT and CT IgG ELISA. Results: A total of 296 women were included for testing; mean age was 29 years. No positive cases of CT and NG were observed using PCR/NAAT. A 7% (22/296) positivity rate for CT was observed using IgG ELISA. No positive association was found between serology and symptoms (vaginal discharge, abdominal pain, dysuria, and dyspareunia) or adverse pregnancy outcomes (miscarriage and stillbirth). Positive relations with CT could be observed with consumption of alcohol, illiteracy, and tenesmus (p-value 0.02–0.03). Discussion: STI prevalence in this study was low, but a high burden of SRH morbidity was observed, with a high symptomatic load. High rates of miscarriage (31%) and stillbirth (8%) were also observed among study subjects. No associations could be found between these ailments and CT infection. These rates are high even for low- and middle-income country standards. Conclusion: This study puts forward high rates of SRH morbidity, and instances of adverse reproductive health outcomes are highlighted in this study, although no associations with CT infection could be found. This warrants more investigation into the causes leading to these complaints in the Indian scenario and potential biases to NAAT testing, such as consumption of over-the-counter antimicrobials

Phenotypic and Genotypic screening of fifty-two rice (Oryza sativa L.) genotypes for desirable cultivars against blast disease.

Magnaporthe oryzae, the rice blast fungus, is one of the most dangerous rice pathogens, causing considerable crop losses around the world. In order to explore the rice blast-resistant sources, initially performed a large-scale screening of 277 rice accessions. In parallel with field evaluations, fifty-two rice accessions were genotyped for 25 major blast resistance genes utilizing functional/gene-based markers based on their reactivity against rice blast disease. According to the phenotypic examination, 29 (58%) and 22 (42%) entries were found to be highly resistant, 18 (36%) and 29 (57%) showed moderate resistance, and 05 (6%) and 01 (1%), respectively, were highly susceptible to leaf and neck blast. The genetic frequency of 25 major blast resistance genes ranged from 32 to 60%, with two genotypes having a maximum of 16 R-genes each. The 52 rice accessions were divided into two groups based on cluster and population structure analysis. The highly resistant and moderately resistant accessions are divided into different groups using the principal coordinate analysis. According to the analysis of molecular variance, the maximum diversity was found within the population, while the minimum diversity was found between the populations. Two markers (RM5647 and K39512), which correspond to the blast-resistant genes Pi36 and Pik, respectively, showed a significant association to the neck blast disease, whereas three markers (Pi2-i, Pita3, and k2167), which correspond to the blast-resistant genes Pi2, Pita/Pita2, and Pikm, respectively, showed a significant association to the leaf blast disease. The associated R-genes might be utilized in rice breeding programmes through marker-assisted breeding, and the identified resistant rice accessions could be used as prospective donors for the production of new resistant varieties in India and around the world

Structure and Biomedical Applications of Amyloid Oligomer Nanoparticles

Amyloid oligomers are nonfibrillar polypeptide aggregates linked to diseases, such as Alzheimer’s and Parkinson’s. Here we show that these aggregates possess a compact, quasi-crystalline architecture that presents significant nanoscale regularity. The amyloid oligomers are dynamic assemblies and are able to release their individual subunits. The small oligomeric size and spheroid shape confer diffusible characteristics, electrophoretic mobility, and the ability to enter hydrated gel matrices or cells. We finally showed that the amyloid oligomers can be labeled with both fluorescence agents and iron oxide nanoparticles and can target macrophage cells. Oligomer amyloids may provide a new biological nanomaterial for improved targeting, drug release, and medical imaging