Spin-torch experiment on reaction centers of Rhodobacter sphaeroides

Photosynthesis is the physico-chemical process by which plants, algae and photosynthetic bacteria use light energy to drive the synthesis of organic compounds. Light-induced electron transfer in photosynthetic reaction centers (RCs) is highly efficient, having a quantum yield close to unity. In RCs of Rhodobacter (R.) sphaeroides wild type (WT), the primary electron donor is a bacteriochlorophyll a (BChl) dimer, called the Special Pair P, comprising two dimer halves PL and PM. Two additional BChl cofactors called accessory BChls (BA and BB), two bacteriopheophytins (_A and _B), two quinones and a non-heme iron are organized into two pseudo-symmetric branches named A and B. After the photo excitation the electron is transferred only via the active __A__ branch. On the other hand, in structurally similar RCs, as that of photosystem I, the electron transfer occurs equally over both branches. Neither the reason for the high efficiency nor that of the directionality of the electron transfer has been elucidated so far. To solve these questions, the solid-state photo-chemically induced nuclear polarization (photo-CIDNP) effect with its dramatic enhancement of local NMR signals provides an analytical tool especially suited for studying electron transfer in photosynthetic RCs. In fact, photo-CIDNP MAS NMR has been applied to explore electronic structures of the electron donors and acceptors in RCsUBL - phd migration 201

FISTULA-IN-ANO: KSHARSUTRA A MINIMAL INVASIVE TREATMENT MODALITY

Fistula-in-ano is troublesome problem encountered in general practice. It consists of 1.6% of all surgical admissions and leads to physical, psychological and social problems. The management consists of multiple modalities with varied results. Present study evaluates medicated seton (Ksharsutra) as a minimal invasive modality of treatment. Methodology: The study was randomized control trial carried out at tertiary care hospital with an aim to assess the efficacy of Ksharsutra Vs fistulectomy. The subjects were clinically diagnosed and MRI confirmed cases of low fistula-in-ano. They were block randomized into two interventional groups. Study group were subjected to introduction of Ksharsutra under local anesthesia while control group under saddle block had a formal fistulectomy done. The outcome measures were wound healing time, hospital stay and recurrence. Results: A total of 63 patients were evaluated of which 33 were allocated to Ksharsutra group and 30 patients underwent fistulectomy. The male: female ratio was 8:1 and mean age of the patients was 38.4 years SD ± 11.03. Perianal sinus with or without pain and discharge was presenting complaints in all patients.1/3rd patient gave history of past incision and drainage while 2/3rd patients had spontaneous rupture. Majority (76%) fistulae were intersphincteric and rest were transsphincteric. The mean healing duration was 5.5 weeks in fistulectomy and 6 weeks in Ksharsutra (p>0.1 [NS]). Recurrence rate and incontinence rates were also significantly not different. Conclusion: The equivalence of results of Ksharsutra with traditional fistulectomy made it an alternative minimal invasive modality of treatment which can be offered on outpatient basis

The resting oxidized state of small laccase analyzed with paramagnetic NMR spectroscopy

nuclei. Two sequence-specific assignments are proposed on the basis of a second-coordination shell variant that also lacks the copper ion at the T1 site, SLAC-T1D/Q291E. This double mutant is found to be exclusively in the RO state, revealing a subtle balance between the RO and the NI states.NWONWO-BOO 022.005.029Macromolecular BiochemistrySolid state NMR/Biophysical Organic Chemistr

Symmetry break of special pair: photochemically induced dynamic nuclear polarization NMR confirms control by nonaromatic substituents

Solid state NMR/Biophysical Organic Chemistr

Large-scale in vitro production, refolding and dimerization of PsbS in different microenvironments

Solid state NMR/Biophysical Organic Chemistr

Bacteriopheophytin a in the active branch of the reaction center of Rhodobacter sphaeroides is not disturbed by the protein matrix as shown by C-13 photo-CIDNP MAS NMR

Solid state NMR/Biophysical Organic Chemistr

wPMLG-5 Spectroscopy of self-aggregated BChl e in natural chlorosomes of Chlorobaculum limnaeum

Solid state NMR/Biophysical Organic Chemistr

Deciphering physiological basis of yield gain in India wheat cultivars

Physiological breeding complementing the conventional approach is increasingly being explored in wheat in view of stagnating annual genetic yield gain. Designing improved plant types required knowledge about physiological traits associated with yield gain in the past. Fourteen wheat varieties including 12 historically important and popular (mega) wheat cultivars and two recently registered varieties were observed for various physiological traits for two years. Both breeding period and genotypes within breeding period accounted for significant differences for most of the physiological traits. Regression analysis indicated curvilinear trend for leaf area index (LAI), flag leaf area, and root length and root weight. Near perfect leaf area index (LAI 5.94) with semi-erect leaves and higher flag leaf area was observed in all time mega variety HD 2967 indicated the importance of plant architecture and crop canopy in yield maximization. Linear declining trend was observed for coleoptile length, number of stomata per cm2 and flag leaf length. Increasing trend for total chlorophyll content and normalized difference for vegetative indices (NDVI) at both vegetative and flowering stage indicated the importance of leaf greenness in yield improvement. Root length has continuously declined except for the latest released varieties, however no such trend was observed for root weight. We propose that grain yield stabilization at still higher level can be achieved by increasing photosynthetic capacity, optimizing the crop canopy slightly less than the optimum, and better partitioning to grain yield through directed physiological based breeding

Rigidified and Hydrophilic DOTA-like Lanthanoid Ligands: Design, Synthesis, and Dynamic Properties

Limiting the dynamics of paramagnetic tags is crucial for the accuracy of the structural information derived from paramagnetic nuclear magnetic resonance (NMR) experiments. A hydrophilic rigid 2,2 ',2 '', 2"'-( 1, 4,7, 10-tetraaz acyclo do de cane-1,4,7,10-tetrayl)tetraacetic acid (DOTA)-like lanthanoid complex was designed and synthesized following a strategy that allows the incorporation of two sets of two adjacent substituents. This resulted in a C2 symmetric hydrophilic and rigid macrocyclic ring, featuring four chiral hydroxyl-methylene substituents. NMR spectroscopy was used to investigate the conformational dynamics of the novel macrocycle upon complexation with europium and compared to DOTA and its derivatives. The twisted square antiprismatic and square antiprismatic conformers coexist, but the former is favored, which is different from DOTA. Two-dimensional 1H exchange spectroscopy shows that ring flipping of the cyclen-ring is suppressed due to the presence of the four chiral equatorial hydroxyl-methylene substituents at proximate positions. The reorientation of the pendant arms causes conformational exchange between two conformers. The reorientation of the coordination arms is slower when the ring flipping is suppressed. This indicates that these complexes are suitable scaffolds to develop rigid probes for paramagnetic NMR of proteins. Due to their hydrophilic nature, it is anticipated that they are less likely to cause protein precipitation than their more hydrophobic counterparts.Bio-organic SynthesisMacromolecular Biochemistr