Ycs4 Subunit of Saccharomyces cerevisiae Condensin Binds DNA and Modulates the Enzyme Turnover.

Condensins play a key role in higher order chromosome organization. In budding yeast Saccharomyces cerevisiae, a condensin complex consists of five subunits: two conserved structural maintenance of chromosome subunits, Smc2 and Smc4, a kleisin Brn1, and two HEAT repeat subunits, Ycg1, which possesses a DNA binding activity, and Ycs4, which can transiently associate with Smc4 and thereby disrupt its association with the Smc2 head. We characterized here DNA binding activity of the non-SMC subunits using an agnostic, model-independent approach. To this end, we mapped the DNA interface of the complex using sulfo-NHS biotin labeling. Besides the known site on Ycg1, we found a patch of lysines at the C-terminal domain of Ycs4 that were protected from biotinylation in the presence of DNA. Point mutations at the predicted protein-DNA interface reduced both Ycs4 binding to DNA and the DNA stimulated ATPase activity of the reconstituted condensin, whereas overproduction of the mutant Ycs4 was detrimental for yeast viability. Notably, the DNA binding site on Ycs4 partially overlapped with its interface with SMC4, revealing an intricate interplay between DNA binding, engagement of the Smc2-Smc4 heads, and ATP hydrolysis and suggesting a mechanism for ATP-modulated loading and translocation of condensins on DNA.

5' isomiR variation is of functional and evolutionary importance.

We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3' and/or 5' end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5' differences and in support of this we report that a 5' isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5' isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes.

Efficient generation of transgenic mice by lentivirus-mediated modification of spermatozoa.

Transgenic technologies conventionally rely on the oocyte as a substrate for genetic modification. Owing to their accessibility, however, male germ cells, including mature sperm, have material advantages for use in transgenesis. Here we have exploited lentiviruses to generate transgenic animals via the male germline. When pseudotyped lentiviral vectors encoding green fluorescent protein (GFP) were incubated with mouse spermatozoa, these sperm were highly successful in producing transgenics. Lentivirally transduced mouse spermatozoa were used in in vitro fertilization (IVF) studies, and when followed by embryo transfer, ≥ 42% of founders were found to be transgenic for GFP. Inverse PCR strategy for integration site analysis demonstrated integration of at least 1 or 2 copies of GFP in the transgenics, mapping to different chromosomes. GFP expression was detected in a wide range of murine tissues, including testis and the transgene was stably transmitted to a third generation of transgenic animals. This relatively simple, yet highly efficient, technique for generating transgenic animals by transducing spermatozoa with lentiviral vectors in vitro is a powerful tool for the study of fertilization/preimplantation development, vertical viral gene transmission, gene function and regulation, and epigenetic inheritance.

Cryptic splice sites and split genes.

We describe a new program called cryptic splice finder (CSF) that can reliably identify cryptic splice sites (css), so providing a useful tool to help investigate splicing mutations in genetic disease. We report that many css are not entirely dormant and are often already active at low levels in normal genes prior to their enhancement in genetic disease. We also report a fascinating correlation between the positions of css and introns, whereby css within the exons of one species frequently match the exact position of introns in equivalent genes from another species. These results strongly indicate that many introns were inserted into css during evolution and they also imply that the splicing information that lies outside some introns can be independently recognized by the splicing machinery and was in place prior to intron insertion. This indicates that non-intronic splicing information had a key role in shaping the split structure of eukaryote genes.

Controlled photonic manipulation of proteins and other nanomaterials.

The ability to controllably handle the smallest materials is a fundamental enabling technology for nanoscience. Conventional optical tweezers have proven useful for manipulating microscale objects but cannot exert enough force to manipulate dielectric materials smaller than about 100 nm. Recently, several near-field optical trapping techniques have been developed that can provide higher trapping stiffness, but they tend to be limited in their ability to reversibly trap and release smaller materials due to a combination of the extremely high electromagnetic fields and the resulting local temperature rise. Here, we have developed a new form of photonic crystal "nanotweezer" that can trap and release on-command Wilson disease proteins, quantum dots, and 22 nm polymer particles with a temperature rise less than ~0.3 K, which is below the point where unwanted fluid mechanical effects will prevent trapping or damage biological targets.

Directrices para presentación de informes de ensayos clínicos sobre intervenciones con inteligencia artificial: extensión CONSORT-AI / Reporting guidelines for clinical trial reports for interventions involving artificial intelligence: the CONSORT-AI extension / Diretrizes para relatórios de ensaios clínicos com intervenções que utilizam inteligência artificial: a extensão CONSORT-AI

resumen está disponible en el texto completo

ABSTRACT The CONSORT 2010 statement provides minimum guidelines for reporting randomized trials. Its widespread use has been instrumental in ensuring transparency in the evaluation of new interventions. More recently, there has been a growing recognition that interventions involving artificial intelligence (AI) need to undergo rigorous, prospective evaluation to demonstrate impact on health outcomes. The CONSORT-AI (Consolidated Standards of Reporting Trials-Artificial Intelligence) extension is a new reporting guideline for clinical trials evaluating interventions with an AI component. It was developed in parallel with its companion statement for clinical trial protocols: SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials-Artificial Intelligence). Both guidelines were developed through a staged consensus process involving literature review and expert consultation to generate 29 candidate items, which were assessed by an international multi-stakeholder group in a two-stage Delphi survey (103 stakeholders), agreed upon in a two-day consensus meeting (31 stakeholders) and refined through a checklist pilot (34 participants). The CONSORT-AI extension includes 14 new items that were considered sufficiently important for AI interventions that they should be routinely reported in addition to the core CONSORT 2010 items. CONSORT-AI recommends that investigators provide clear descriptions of the AI intervention, including instructions and skills required for use, the setting in which the AI intervention is integrated, the handling of inputs and outputs of the AI intervention, the human-AI interaction and provision of an analysis of error cases. CONSORT-AI will help promote transparency and completeness in reporting clinical trials for AI interventions. It will assist editors and peer reviewers, as well as the general readership, to understand, interpret and critically appraise the quality of clinical trial design and risk of bias in the reported outcomes.

RESUMO A declaração CONSORT 2010 apresenta diretrizes mínimas para relatórios de ensaios clínicos randomizados. Seu uso generalizado tem sido fundamental para garantir a transparência na avaliação de novas intervenções. Recentemente, tem-se reconhecido cada vez mais que intervenções que incluem inteligência artificial (IA) precisam ser submetidas a uma avaliação rigorosa e prospectiva para demonstrar seus impactos sobre os resultados de saúde. A extensão CONSORT-AI (Consolidated Standards of Reporting Trials - Artificial Intelligence) é uma nova diretriz para relatórios de ensaios clínicos que avaliam intervenções com um componente de IA. Ela foi desenvolvida em paralelo à sua declaração complementar para protocolos de ensaios clínicos, a SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials - Artificial Intelligence). Ambas as diretrizes foram desenvolvidas por meio de um processo de consenso em etapas que incluiu revisão da literatura e consultas a especialistas para gerar 29 itens candidatos. Foram feitas consultas sobre esses itens a um grupo internacional composto por 103 interessados diretos, que participaram de uma pesquisa Delphi em duas etapas. Chegou-se a um acordo sobre os itens em uma reunião de consenso que incluiu 31 interessados diretos, e os itens foram refinados por meio de uma lista de verificação piloto que envolveu 34 participantes. A extensão CONSORT-AI inclui 14 itens novos que, devido à sua importância para as intervenções de IA, devem ser informados rotineiramente juntamente com os itens básicos da CONSORT 2010. A CONSORT-AI preconiza que os pesquisadores descrevam claramente a intervenção de IA, incluindo instruções e as habilidades necessárias para seu uso, o contexto no qual a intervenção de IA está inserida, considerações sobre o manuseio dos dados de entrada e saída da intervenção de IA, a interação humano-IA e uma análise dos casos de erro. A CONSORT-AI ajudará a promover a transparência e a integralidade nos relatórios de ensaios clínicos com intervenções que utilizam IA. Seu uso ajudará editores e revisores, bem como leitores em geral, a entender, interpretar e avaliar criticamente a qualidade do desenho do ensaio clínico e o risco de viés nos resultados relatados.

Directrices para los protocolos de ensayos clínicos de intervenciones con inteligencia artificial: la extensión SPIRIT-AI / Guidelines for clinical trial protocols for interventions involving artificial intelligence: the SPIRIT-AI extension / Diretrizes para protocolos de ensaios clínicos com intervenções que utilizam inteligência artificial: a extensão SPIRIT-AI

resumen está disponible en el texto completo

ABSTRACT The SPIRIT 2013 statement aims to improve the completeness of clinical trial protocol reporting by providing evidence-based recommendations for the minimum set of items to be addressed. This guidance has been instrumental in promoting transparent evaluation of new interventions. More recently, there has been a growing recognition that interventions involving artificial intelligence (AI) need to undergo rigorous, prospective evaluation to demonstrate their impact on health outcomes. The SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials-Artificial Intelligence) extension is a new reporting guideline for clinical trial protocols evaluating interventions with an AI component. It was developed in parallel with its companion statement for trial reports: CONSORT-AI (Consolidated Standards of Reporting Trials-Artificial Intelligence). Both guidelines were developed through a staged consensus process involving literature review and expert consultation to generate 26 candidate items, which were consulted upon by an international multi-stakeholder group in a two-stage Delphi survey (103 stakeholders), agreed upon in a consensus meeting (31 stakeholders) and refined through a checklist pilot (34 participants). The SPIRIT-AI extension includes 15 new items that were considered sufficiently important for clinical trial protocols of AI interventions. These new items should be routinely reported in addition to the core SPIRIT 2013 items. SPIRIT-AI recommends that investigators provide clear descriptions of the AI intervention, including instructions and skills required for use, the setting in which the AI intervention will be integrated, considerations for the handling of input and output data, the human-AI interaction and analysis of error cases. SPIRIT-AI will help promote transparency and completeness for clinical trial protocols for AI interventions. Its use will assist editors and peer reviewers, as well as the general readership, to understand, interpret and critically appraise the design and risk of bias for a planned clinical trial.

RESUMO A declaração SPIRIT 2013 tem como objetivo melhorar a integralidade dos relatórios dos protocolos de ensaios clínicos, fornecendo recomendações baseadas em evidências para o conjunto mínimo de itens que devem ser abordados. Essas orientações têm sido fundamentais para promover uma avaliação transparente de novas intervenções. Recentemente, tem-se reconhecido cada vez mais que intervenções que incluem inteligência artificial (IA) precisam ser submetidas a uma avaliação rigorosa e prospectiva para demonstrar seus impactos sobre os resultados de saúde. A extensão SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials - Artificial Intelligence) é uma nova diretriz de relatório para protocolos de ensaios clínicos que avaliam intervenções com um componente de IA. Essa diretriz foi desenvolvida em paralelo à sua declaração complementar para relatórios de ensaios clínicos, CONSORT-AI (Consolidated Standards of Reporting Trials - Artificial Intelligence). Ambas as diretrizes foram desenvolvidas por meio de um processo de consenso em etapas que incluiu revisão da literatura e consultas a especialistas para gerar 26 itens candidatos. Foram feitas consultas sobre esses itens a um grupo internacional composto por 103 interessados diretos, que participaram de uma pesquisa Delphi em duas etapas. Chegou-se a um acordo sobre os itens em uma reunião de consenso que incluiu 31 interessados diretos, e os itens foram refinados por meio de uma lista de verificação piloto que envolveu 34 participantes. A extensão SPIRIT-AI inclui 15 itens novos que foram considerados suficientemente importantes para os protocolos de ensaios clínicos com intervenções que utilizam IA. Esses itens novos devem constar dos relatórios de rotina, juntamente com os itens básicos da SPIRIT 2013. A SPIRIT-AI preconiza que os pesquisadores descrevam claramente a intervenção de IA, incluindo instruções e as habilidades necessárias para seu uso, o contexto no qual a intervenção de IA será integrada, considerações sobre o manuseio dos dados de entrada e saída, a interação humano-IA e a análise de casos de erro. A SPIRIT-AI ajudará a promover a transparência e a integralidade nos protocolos de ensaios clínicos com intervenções que utilizam IA. Seu uso ajudará editores e revisores, bem como leitores em geral, a entender, interpretar e avaliar criticamente o delineamento e o risco de viés de um futuro estudo clínico.

Validation and divergence of the activation energy barrier crossing transition at the AOT/lecithin reverse micellar interface.

In this report, the validity and divergence of the activation energy barrier crossing model for the bound to free type water transition at the interface of the AOT/lecithin mixed reverse micelle (RM) has been investigated for the first time in a wide range of temperatures by time-resolved solvation of fluorophores. Here, picosecond-resolved solvation dynamics of two fluorescent probes, ANS (1-anilino-8-naphthalenesulfonic acid, ammonium salt) and Coumarin 500 (C-500), in the mixed RM have been carefully examined at 293, 313, 328, and 343 K. Using the dynamic light scattering (DLS) technique, the size of the mixed RMs at different temperatures was found to have an insignificant change. The solvation process at the reverse micellar interface has been found to be the activation energy barrier crossing type, in which interface-bound type water molecules get converted into free type water molecules. The activation energies, Ea, calculated for ANS and C-500 are 7.4 and 3.9 kcal mol(-1), respectively, which are in good agreement with that obtained by molecular dynamics simulation studies. However, deviation from the regular Arrhenius type behavior was observed for ANS around 343 K, which has been attributed to the spatial heterogeneity of the probe environments. Time-resolved fluorescence anisotropy decay of the probes has indicated the existence of the dyes in a range of locations in RM. With the increase in temperature, the overall anisotropy decay becomes faster revealing the lability of the microenvironment at elevated temperatures.

The gamma ray detection threshold temperature of different superheated droplet detectors.

The response of superheated droplet detectors (SDD) loaded with four different active liquids, R-12 (CCl2F2), R-114 (C2Cl2F4), R-134a (C2H2F4) and R-610 (C4F10) have been studied to obtain the gamma ray detection threshold temperature (Tγ) of the respective detectors. A 137Cs gamma ray source is used for this study. To obtain Tγ from the experimental data a phenomenological model has been used. Result indicates that Tγ maintains a linear relationship with the limit of superheat (Tlim) of different active liquids used in SDD. It indicates that the limit of superheat of a liquid can be used for the prediction of its gamma ray detection threshold temperature.

Directrices para los protocolos de ensayos clínicos de intervenciones con inteligencia artificial: la extensión SPIRIT-AI / Guidelines for clinical trial protocols for interventions involving artificial intelligence: the SPIRIT-AI extension / Diretrizes para protocolos de ensaios clínicos com intervenções que utilizam inteligência artificial: a extensão SPIRIT-AI

resumen está disponible en el texto completo

ABSTRACT The SPIRIT 2013 statement aims to improve the completeness of clinical trial protocol reporting by providing evidence-based recommendations for the minimum set of items to be addressed. This guidance has been instrumental in promoting transparent evaluation of new interventions. More recently, there has been a growing recognition that interventions involving artificial intelligence (AI) need to undergo rigorous, prospective evaluation to demonstrate their impact on health outcomes. The SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials-Artificial Intelligence) extension is a new reporting guideline for clinical trial protocols evaluating interventions with an AI component. It was developed in parallel with its companion statement for trial reports: CONSORT-AI (Consolidated Standards of Reporting Trials-Artificial Intelligence). Both guidelines were developed through a staged consensus process involving literature review and expert consultation to generate 26 candidate items, which were consulted upon by an international multi-stakeholder group in a two-stage Delphi survey (103 stakeholders), agreed upon in a consensus meeting (31 stakeholders) and refined through a checklist pilot (34 participants). The SPIRIT-AI extension includes 15 new items that were considered sufficiently important for clinical trial protocols of AI interventions. These new items should be routinely reported in addition to the core SPIRIT 2013 items. SPIRIT-AI recommends that investigators provide clear descriptions of the AI intervention, including instructions and skills required for use, the setting in which the AI intervention will be integrated, considerations for the handling of input and output data, the human-AI interaction and analysis of error cases. SPIRIT-AI will help promote transparency and completeness for clinical trial protocols for AI interventions. Its use will assist editors and peer reviewers, as well as the general readership, to understand, interpret and critically appraise the design and risk of bias for a planned clinical trial.

RESUMO A declaração SPIRIT 2013 tem como objetivo melhorar a integralidade dos relatórios dos protocolos de ensaios clínicos, fornecendo recomendações baseadas em evidências para o conjunto mínimo de itens que devem ser abordados. Essas orientações têm sido fundamentais para promover uma avaliação transparente de novas intervenções. Recentemente, tem-se reconhecido cada vez mais que intervenções que incluem inteligência artificial (IA) precisam ser submetidas a uma avaliação rigorosa e prospectiva para demonstrar seus impactos sobre os resultados de saúde. A extensão SPIRIT-AI (Standard Protocol Items: Recommendations for Interventional Trials - Artificial Intelligence) é uma nova diretriz de relatório para protocolos de ensaios clínicos que avaliam intervenções com um componente de IA. Essa diretriz foi desenvolvida em paralelo à sua declaração complementar para relatórios de ensaios clínicos, CONSORT-AI (Consolidated Standards of Reporting Trials - Artificial Intelligence). Ambas as diretrizes foram desenvolvidas por meio de um processo de consenso em etapas que incluiu revisão da literatura e consultas a especialistas para gerar 26 itens candidatos. Foram feitas consultas sobre esses itens a um grupo internacional composto por 103 interessados diretos, que participaram de uma pesquisa Delphi em duas etapas. Chegou-se a um acordo sobre os itens em uma reunião de consenso que incluiu 31 interessados diretos, e os itens foram refinados por meio de uma lista de verificação piloto que envolveu 34 participantes. A extensão SPIRIT-AI inclui 15 itens novos que foram considerados suficientemente importantes para os protocolos de ensaios clínicos com intervenções que utilizam IA. Esses itens novos devem constar dos relatórios de rotina, juntamente com os itens básicos da SPIRIT 2013. A SPIRIT-AI preconiza que os pesquisadores descrevam claramente a intervenção de IA, incluindo instruções e as habilidades necessárias para seu uso, o contexto no qual a intervenção de IA será integrada, considerações sobre o manuseio dos dados de entrada e saída, a interação humano-IA e a análise de casos de erro. A SPIRIT-AI ajudará a promover a transparência e a integralidade nos protocolos de ensaios clínicos com intervenções que utilizam IA. Seu uso ajudará editores e revisores, bem como leitores em geral, a entender, interpretar e avaliar criticamente o delineamento e o risco de viés de um futuro estudo clínico.

Direct conjugation of semiconductor nanocrystals to a globular protein to study protein-folding intermediates.

In this Article, we study the development of semiconductor nanocrystals (quantum dots of average diameter less than 2 nm) directly conjugated to a transporter protein human serum albumin (HSA) as fluorescent biological labels. Förster resonance energy transfer (FRET) from the amino acid tryptophan (Trp214) to quantum dot in HSA is monitored to follow the local and global changes in the protein structure during thermal unfolding and refolding processes. This study is likely to attract widespread attention as a powerful tool for the study of protein folding.

Exploring Condensins with Magnetic Tweezers.

The signature activity of condensins as DNA reshaping machines is their ability to impose the giant loop architecture onto the chromosome. At the heart of this activity lies the propensity of the proteins to assemble into macromolecular clusters that bring distant DNA segments together. This gives rise to a rich dynamic behavior when the proteins are presented with the DNA substrate. The protocols in this section describe how the interaction between Escherichia coli condensin MukB and DNA proceeds in real time as observed using magnetic tweezers.

Note: A new optical method for the detection of bubble nucleation in superheated droplet detector.

A superheated droplet detector (SDD) consists of a large number of micron-sized superheated liquid drops suspended in a gel medium. The vaporization of a superheated drop is associated with the emission of an acoustic signal. A novel optical method is developed for the detection of this acoustic signal. In this method, a probe-bubble picks up the acoustic signal, and the oscillation of the probe-bubble is detected by employing a laser and phototransistor. The method can detect vaporization of an individual superheated drop in real-time and can be used for studying the response of SDDs to ionizing radiations.

Bifurcation kinetics of drug uptake by Gram-negative bacteria.

Cell envelopes of many bacteria consist of two membranes studded with efflux transporters. Such organization protects bacteria from the environment and gives rise to multidrug resistance. We report a kinetic model that accurately describes the permeation properties of this system. The model predicts complex non-linear patterns of drug uptake complete with a bifurcation, which recapitulate the known experimental anomalies. We introduce two kinetic parameters, the efflux and barrier constants, which replace those of Michaelis and Menten for trans-envelope transport. Both compound permeation and efflux display transitions, which delineate regimes of efficient and inefficient efflux. The first transition is related to saturation of the transporter by the compound and the second one behaves as a bifurcation and involves saturation of the outer membrane barrier. The bifurcation was experimentally observed in live bacteria. We further found that active efflux of a drug can be orders of magnitude faster than its diffusion into a cell and that the efficacy of a drug depends both on its transport properties and therapeutic potency. This analysis reveals novel physical principles in the behavior of the cellular envelope, creates a framework for quantification of small molecule permeation into bacteria, and should invigorate structure-activity studies of novel antibiotics.

Direct observation of protein folding in nanoenvironments using a molecular ruler.

We observe folding of horse heart cytochrome c in various environments including nano-compartments (micelles and reverse micelles). Using picosecond-resolved Förster resonance energy transfer (FRET) dynamics of an extrinsic covalently attached probe dansyl (donor) at the surface of the protein to a heme group (acceptor) embedded inside the protein, we measured angstrom-resolved donor-acceptor distances in the environments. The overall structural perturbations of the protein revealed from the FRET experiments are in close agreement with our circular dichroism (CD) and dynamic light scattering (DLS) studies on the protein in a variety of solution conditions. The change of segmental motion of the protein due to imposed restriction in the nano-compartments compared to that in bulk buffer is also revealed by temporal fluorescence anisotropy of the dansyl probe.

Ultrafast photoinduced deligation and ligation dynamics: DCM in micelle and micelle-enzyme complex.

We report studies on diffusion controlled deligation and ligation dynamics of a probe ligand 4-(dicyanomethylene)-2-methyl-6-(p-dimethylamino-styryl) 4H-pyran (DCM) with cationic cetyltrimethylammonium bromide (CTAB) micelles. In order to investigate the effect of spatial heterogeneity on the dynamics we study the DCM labeled micelle upon complexation with an enzyme alpha-chymotrypsin (CHT). The variation of fluorescence line-width (Gamma(t)) of DCM in the complex and also in the micelle indicates the diffusion dynamics of DCM through various environments of different polarities. The temporal behavior of Gamma(t) reveals that at 50 mM CTAB concentration the excited DCM traverses 6.5 Angstrom distance from the surface of a host micelle (deligation) before entering to a stern layer of another adjacent micelle (ligation). From neutron scattering experiment the distance 6.5 Angstrom is found to be the thickness of a stern layer of CTAB micelle. No indication of ligation has been found at 2 mM CTAB concentration as the intermicellar distance is estimated to be very large (416 Angstrom) compared to the previous case. The dynamical behavior of Gamma(t) is also indicative of significantly slower diffusion of the ligand molecules (DCM) at the surface of the micelle in presence and absence of the enzyme compared to that in the bulk buffer. We have also studied the dynamics of solvation and local geometrical restriction on the probe DCM at the micellar surface with and without CHT. With picosecond time resolution, we found time constants of the solvation relaxation processes of the DCM labeled enzyme-micelle complex to be 230 ps (45%) and 870 ps (55%), which were comparable to those of the micelle without the enzyme. The time dependent anisotropy revealing local orientational motions of the probe in the complex was also found to be similar to that of DCM at the micellar surface in absence of CHT. These studies attempt to link the dynamical features for insight into the ligand mediated intercellular communication and the biological function of the enzyme alpha-chymotrypsin upon complexation with the CTAB micelle.