Helix packing motif common to the crystal structures of two undecapeptides containing dehydrophenylalanine residues: implications for the de novo design of helical bundle super secondary structural modules

De novo designed peptide based super secondary structures are expected to provide scaffolds for the incorporation of functional sites as in proteins. Self-association of peptide helices of similar screw sense, mediated by weak interactions, has been probed by the crystal structure determination of two closely related peptides: Ac-Gly1-Ala2-ΔPhe3-Leu4-Val5-ΔPhe6-Leu7-Val8-ΔPhe9-Ala10-Gly11-NH2 (I) and Ac-Gly1-Ala2-ΔPhe3-Leu4-Ala5-ΔPhe6-Leu7-Ala8-ΔPhe9-Ala10-Gly11-NH2 (II). The crystal structures determined to atomic resolution and refined to R factors 8.12 and 4.01%, respectively, reveal right-handed 310-helical conformations for both peptides. CD has also revealed the preferential formation of right-handed 310-helical conformations for both molecules. Our aim was to critically analyze the packing of the helices in the solid state with a view to elicit clues for the design of super secondary structural motifs such as two, three, and four helical bundles based on helix-helix interactions. An important finding is that a packing motif could be identified common to both the structures, in which a given peptide helix is surrounded by six other helices reminiscent of transmembrane seven helical bundles. The outer helices are oriented either parallel or antiparallel to the central helix. The helices interact laterally through a combination of N-H ... O, C-H ... O, and C-H ... π hydrogen bonds. Layers of interacting leucine residues are seen in both peptide crystal structures. The packing of the peptide helices in the solid state appears to provide valuable leads for the design of super secondary structural modules such as two, three, or four helix bundles by connecting adjacent antiparallel helices through suitable linkers such as tetraglycine segment

Creativity workshops creating child-friendly spaces

On the makeshift stage were six students of class 4 and 5 of a government primary school in a remote village called Thirtha, in Surpur taluk of Yadgir district. They were in the age group of 10 to 12 years. They were performing a five-minute role play on ‘Gram Panchayat’1 and had been given just 15 minutes to prepare on a serious subject

A Review on COVID-19 Outbreak Marketing and Corporate Social Responsibility (CSR)

The research paper focuses on the evidence-based on a preliminary study conducted on how the COVID-19 outbreak might affect the evolution of business obligations to discharge the activities which could uplift society and marketing. Ironically, it is true that the pandemic has provided an excellent opportunity for corporations to redirect their focus points and to comprehend the newer dimension of customers’ ethical decision-making process. This outbreak has a significant impact on marketing and magnifies the approach towards the strategic marketing efforts drawn by firms as opposed to content marketing. We conclude the study by outlining a number of research issues and areas that have the potential to be productive

Guru chethana - teacher professional development a government of Karnataka initiative

‘The status of the teacher reflects the socio-cultural ethos of the society; it is said that no people can rise above the level of its teachers’ - such exhortations are indeed expressions of the important role played by the teachers as transmitters, inspirers and promoters of the eternal quest for knowledge in human beings. All of us aspire for a good society that is humane, equitable and sustainable. It is assumed that school education provides the foundation for it. Education could bring such society through non-violent and sustained manner. India attempts education for every individual amending fundamental rights where it ensured Right of Free and Compulsory Education. As result of this, it is being attempted to ensure access for each child in terms of schooling as well in quality. The reservation of seats for vulnerable family children in private schools is part of the same. Through this, the education of every child became a mandate of the Government. Both the Central and State governments have been putting in their best efforts to ensure easy access of school for all children and promoting regular attendance through various government programmes. India has achieved a lot in terms of enrolment, and significantly accomplished attendance of students in primary schools. The issue that remains unaddressed is quality of education. Many reports such as ASER, NAS identified gaps in learning levels of students across the subjects. It has become serious issue in the school education these days and has been identified as a key concern in school education. The quality of education is considerably determined by teachers and their engagements in the classroom. Teacher professional abilities eventually contribute for quality delivery of education in the schools along with other requirement such as infrastructure, PTR (Pupil Teacher Ratio), school leadership, etc

Assessment : notes from the field

Every educational intervention expects to lead to improvement in the learning outcomes of students. Many interventions in India focus on building teacher capacity, creating a learning- conducive atmosphere or bridging the gap between the school and community which are then expected to positively impact learning outcome of students. Assessment is a significant part of an intervention to systematically understand improvement in the learning outcomes of the students, and helps teachers or facilitators to understand problems that students face and design processes for improvement. It also helps teachers and functionaries to understand preparation for teaching better. Azim Premji Foundation has had experience of conceiving and administering assessment tools and processes in schools to evaluate the impact of our interventions and to promote learning

Teacher learning centre: an effective space for teacher development

The quality of a school depends on the quality of its teachers. What students learn in schools is directly associated to what and how teachers teach. What and how teachers teach, in turn, depends on the teachers’ knowledge, skills, motivation and commitment. If school teachers are expected to bring about significant changes in their approach of teaching, the same change must precede and find a place in their pre-service education and programmes for in service professional development. Many teachers in government schools are willing to enhance their knowledge, learn new things and adapt changes as per the changing demands of classroom. A large number of government school teachers are serving in rural areas. It is necessary to examine the facilities available for such teachers to upgrade their subject knowledge and receive support in addressing day-to-day academic challenges. It is also essential to understand basic mechanisms established to provide academic support to teachers

Occupational health in information technology professionals - An Ayurvedic Purview

Occupational Health mainly aims at promotion and maintenance of the highest degree of physical, mental, social wellbeing of workers in all occupations. Working environment is also important for a person, as he spends nearly 6-8 hours/day and about a minimum of 3 decades of his life span in his respective occupations. Now, around the world the occupational health personnel are witnessing the emergence of health-related problems in computer users. In the present era, younger generation is behind the technology and attractive job opportunities as it affects the total economy of the country. Some of the commonly seen health problems among them are Repetitive Stress Injury (RSI), Ocular disorders and Stress. The principles of Ayurveda are focusing on promoting health and preventing the diseases. In regards to this, following Dinacharya, Ritucharya, Sadvritta, Achara Rasayana have a major role to play in it. Thus, by adopting the regimes told by our Acharyas will contribute effectively in improving the quality of health and standards of living in Informational Technology Professionals

Anodic Polarization of Copper Single Crystal Planes in Sulphuric Acid

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Acute necrotizing encephalopathy in a young adult with EBV and COVID19 co-infection: A case report

Clinical history: A 22yr old female came with complaints of fever and altered sensorium since 2 days. Serology showed positive for Epstein-Barr virus (EBV) and COVID-19 IgG antibodies. Laboratory investigations revealed elevated total counts & inflammatory markers

Observation of glycine zipper and unanticipated occurrence of ambidextrous helices in the crystal structure of a chiral undecapeptide

<p>Abstract</p> <p>Background</p> <p>The <it>de novo </it>design of peptides and proteins has recently surfaced as an approach for investigating protein structure and function. This approach vitally tests our knowledge of protein folding and function, while also laying the groundwork for the fabrication of proteins with properties not precedented in nature. The success of these studies relies heavily on the ability to design relatively short peptides that can espouse stable secondary structures. To this end, substitution with α, β-dehydroamino acids, especially α, β-dehydrophenylalanine (ΔPhe) comes in use for spawning well-defined structural motifs. Introduction of ΔPhe induces β-bends in small and 3₁₀-helices in longer peptide sequences.</p> <p>Results</p> <p>The present report is an investigation of the effect of incorporating two glycines in the middle of a ΔPhe containing undecapeptide. A de novo designed undecapeptide, Ac-Gly¹-Ala²-ΔPhe³-Leu⁴-Gly⁵-ΔPhe⁶-Leu⁷-Gly⁸-ΔPhe⁹-Ala¹⁰-Gly¹¹-NH₂, was synthesized and characterized using X-ray diffraction and Circular Dichroism spectroscopic methods. Crystallographic studies suggest that, despite the presence of L-amino acid (L-Ala and L-Leu) residues in the middle of the sequence, the peptide adopts a 3₁₀-helical conformation of ambidextrous screw sense, one of them a left-handed (A) and the other a right-handed (B) 3₁₀-helix with A and B being antiparallel to each other. However, CD studies reveal that the undecapeptide exclusively adopts a right-handed 3₁₀-helical conformation. In the crystal packing, three different interhelical interfaces, Leu-Leu, Gly-Gly and ΔPhe-ΔPhe are observed between the helices A and B. A network of C-H...O hydrogen bonds are observed at ΔPhe-ΔPhe and Gly-Gly interhelical interfaces. An important feature observed is the occurrence of glycine zipper motif at Gly-Gly interface. At this interface, the geometric pattern of interhelical interactions seems to resemble those observed between helices in transmembrane (TM) proteins.</p> <p>Conclusion</p> <p>The present design strategy can thus be exploited in future work on de novo design of helical bundles of higher order and compaction utilizing ΔPhe residues along with GXXG motif.</p