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Synthetic Materials (synthetic + material)

Distribution by Scientific Domains

Polymers and Materials Science	35%
Chemistry	35%
Medical Sciences	30%

Selected Abstracts

A Smelling Trip into the Past: The Influence of Synthetic Materials on the History of Perfumery

CHEMISTRY & BIODIVERSITY, Issue 6 2008
Nicolaï, Patricia de
Abstract Contemporary perfumery has its roots in the work of the past, and many of the perfumes from this time have long since disappeared. What follows is a short account of some of the most famous perfumes from the past which have been inspired by the novel synthetic materials of the time. These important creations include, ,Fougère Royale' by Houbigant (1884) containing coumarin (1), ,Jicky' by Guerlain (1889) containing vanillin (2) and linalool (3), ,Vera Violetta' by Roger & Gallet (1892) containing , - and , -ionone (4 and 5, resp.), ,Trèfle Incarnat' by Piver (1898) containing isoamyl salicylate (6), ,La Rose Jacqueminot' of Coty (1904) containing Rhodinol (7), ,Après l'Ondée' by Guerlain (1906) containing para- anisaldehyde (8), ,Quelques Fleurs' by Houbigant (1912) containing hydroxycitronellal (9), ,N°5' by Chanel (1921) containing the aldehydes C-10 (10), C-110 (11), and C-12 (12), ,Nuit De Noël' by Caron (1922) containing 6-isobutylquinoline (14), and ,Femme' by Rochas (1944) containing the so-called ,aldehyde C-14' (15, , -undecalactone). The Osmotheque, the International Conservatory of Perfumes, was launched in 1990 and is regarded as a primary source of knowledge for the history of perfumery. Its vocation is to compile an amazing collection of 1700 perfumes (400 of them almost forgotten fragrances) , jewels of perfumery. [source]

Iatrogenic Creutzfeldt,Jakob disease subsequent to dural graft: persisting risk after 1987

EUROPEAN JOURNAL OF NEUROLOGY, Issue 5 2003
C. Boutoleau
The first case of Creutzfeldt,Jakob disease (CJD) related to the use of a dura mater graft of cadaveric origin was identified in 1987 and this procedure is now considered as one of the main causes of iatrogenic CJD. Although the decontamination procedure for the preparation of graft material was modified, the product was withdrawn from the market in many countries a few years later and replaced by synthetic material. In this context, two patients treated in our institution developed CJD following a cadaveric dural graft performed after cerebral and lumbar trauma. Their clinical presentation, showing predominant cerebellar symptoms, late deterioration and myoclonic jerks, and a rapid disease course until death, was similar to that of previously reported cases involving the iatrogenic form. As the graft for one of the patients was performed in 1991 (several years after modification of the decontamination procedure), this fourth reported case suggests that the risk of iatrogenic CJD may have persisted in some patients treated after 1987, when grafts of cadaveric origin were totally abandoned. [source]

Topical palmitoyl pentapeptide provides improvement in photoaged human facial skin,

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 3 2005
L. R. Robinson
Synopsis The palmitoyl pentapeptide palmitoyl-lysine-threonine-threonine-lysine-serine (pal-KTTKS) is a synthetic material that was designed as a topical agent to stimulate collagen production and thus provide a skin anti-wrinkle benefit. To determine if pal-KTTKS is effective, the clinical study reported here was conducted. Caucasian female subjects (n = 93, aged 35,55) participated in a 12-week, double-blind, placebo-controlled, split-face, left,right randomized clinical study assessing two topical products: moisturizer control product vs. the same moisturizer product containing 3 ppm pal-KTTKS. Pal-KTTKS was well tolerated by the skin and provided significant improvement vs. placebo control for reduction in wrinkles/fine lines by both quantitative technical and expert grader image analysis. In self-assessments, subjects also reported significant fine line/wrinkle improvements and noted directional effects for other facial improvement parameters. Résumé Le pentapeptide palmitoyl-lysine-thréonine-lysine-sérine (pal-KTTKS) est un composé synthétique décrit comme agent topique stimulant la production de collagène et possédant donc des propriétés anti-rides. L'efficacité du pal-KTTKL a étéévaluée dans l'étude clinique faisant l'objet de cet article. Des femmes de type caucasien (n = 93, de 35 à 55 ans) ont participé pendant 12 semaines à un test en double aveugle avec placébo, en apparié par demie face comparant deux produits topiques: un produit témoin hydratant et le même produit contenant 3 ppm de pal-KTTKS. Bien toléré par la peau, le pal-KTTKS a montré par rapport au témoin, une amélioration significative dans la réduction des rides et ridules que se soit par des techniques quantitatives et par l'analyse d'image quantifiée par un expert. Dans le cadre d'auto-évaluations, les sujets ont fait état d'améliorations significatives et attiré l'attention sur des effets pouvant servir de pistes pour d'autres paramètres d'amélioration faciale. [source]

SELECTED COCHRANE SYSTEMATIC REVIEWS Absorbable Synthetic Versus Catgut Suture Material for Perineal Repair

BIRTH, Issue 2 2000
C. Kettle
A substantive amendment to this systematic review was last made on 19 May 1999. Cochrane reviews are regularly checked and updated if necessary. ABSTRACT Background and objectives: Approximately 70% of women will experience some degree of perineal trauma following vaginal delivery and will require stitches. This may result in perineal pain and superficial dyspareunia. The objective of this review was to assess the effects of absorbable synthetic suture material as compared with catgut on the amount of short- and long-term pain experienced by mothers following perineal repair. Search strategy: We searched the Cochrane Pregnancy and Childbirth Group trials register. Selection criteria: Randomised trials comparing absorbable synthetic (polyglycolic acid and polyglactin) with plain or chromic catgut suture for perineal repair in mothers after vaginal delivery. Data collection and analysis: Trial quality was assessed independently by two reviewers. Data were extracted by one reviewer and checked by the second reviewer. Main results: Eight trials were included. Compared with catgut, the polyglycolic acid and polyglactin groups were associated with less pain in first three days (odds ratio 0.62, 95% confidence interval 0.54,0.71). There was also less need for analgesia (odds ratio 0,63, 95% confidence interval 0.52,0.77) and less suture dehiscence (odds ratio 0.45, 95% confidence interval 0.29,0.70). There was no significant difference in long-term pain (odds ratio 0.81, 95% confidence interval 0.61,1.08). Removal of suture material was significantly more common in the polyglycolic acid and polyglactin groups (odds ratio 2.01, 95% confidence interval 1.56,2.58). There was no difference in the amount of dyspareunia experienced by women. Reviewers' conclusions: Absorbable synthetic suture material (in the form of polyglycolic acid and polyglactin sutures) for perineal repair following childbirth appears to decrease women's experience of short-term pain. The length of time taken for the synthetic material to be absorbed is of concern. A trial addressing the use of polyglactin has recently been completed and this has been included in this updated review. Citation: Kettle C, Johanson RB. Absorbable synthetic versus catgut suture material for perineal repair (Cochrane Review). In: The Cochrane Library, Issue 4, 1999, Oxford: Update Software. ,,, The preceding report is an abstract of regularly updated, systematic reviews prepared and maintained by the Cochrane Collaboration. The full texts of the reviews are available in The Cochrane Library (ISSN 1464-780X). Seehttp://www.update-software.com/cochrane.htmor contact Update Software,info@update.co.uk, for information on subscribing to The Cochrane Library in your area. Update Software Ltd, Summertown Pavilion, Middle Way, Oxford OX2 7LG, United Kingdom (Tel.: +44 1865 513902; Fax: +44 1865 516918). [source]

Perfume Formulation: Words and Chats

CHEMISTRY & BIODIVERSITY, Issue 6 2008
Céline Ellena
Abstract What does it mean to create fragrances with materials from chemistry and/or from nature? How are they used to display their characteristic differences, their own personality? Is it easier to create with synthetic raw materials or with essential oils? This review explains why a perfume formulation corresponds in fact to a conversation, an interplay between synthetic and natural perfumery materials. A synthetic raw material carries a single information, and usually is very linear. Its smell is uniform, clear, and faithful. Natural raw materials, on the contrary, provide a strong, complex and generous image. While a synthetic material can be seen as a single word, a natural one such as rose oil could be compared to chatting: cold, warm, sticky, heavy, transparent, pepper, green, metallic, smooth, watery, fruity, full of information. Yet, if a very small amount of the natural material is used, nothing happens, the fragrance will not change. However, if a large amount is used, the rose oil will swallow up everything else. The fragrance will smell of nothing else except rose! To formulate a perfume is not to create a culinary recipe, with only dosing the ingredients in well-balanced amounts. To formulate rather means to flexibly knit materials together with a lively stitch, meeting or repelling each other, building a pleasant form, which is neither fixed, nor solid, nor rigid. A fragrance has an overall structure, which ranges from a clear sound, made up of stable, unique, and linear items, to a background chat, comfortable and reassuring. But that does, of course, not mean that there is only one way of creating a fragrance! [source]

Bioinspired Structural Material Exhibiting Post-Yield Lateral Expansion and Volumetric Energy Dissipation During Tension

ADVANCED FUNCTIONAL MATERIALS, Issue 18 2010
Lifeng Wang
Abstract Nature has inspired the design of improved synthetic materials that achieve superior and more efficient mechanical performance. Here microstructures inspired by the inner nacreous layer of seashells are designed and their mechanical properties including stiffness, strength, and energy dissipation are computed using micromechanical analysis. The hierarchical mineral/polymer microstructure can be tailored to achieve not only stiffness and strength, but also lateral plastic expansion during tension providing a volumetric energy dissipation mechanism. [source]

Synthetic Hydrophilic Materials with Tunable Strength and a Range of Hydrophobic Interactions,

ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010
Olha Hoy
Abstract The ability to vary, adjust, and control hydrophobic interactions is crucial in manipulating interactions between biological objects and the surface of synthetic materials in aqueous environment. To this end a grafted polymer layer (multi-component mixed polymer brush) is synthesized that is capable of reversibly exposing nanometer-sized hydrophobic fragments at its hydrophilic surface and of tuning, turning on, and turning off the hydrophobic interactions. The reversible switching occurs in response to changes in the environment and alters the strength and range of attractive interactions between the layer and hydrophobic or amphiphilic probes in water. The grafted layer retains its overall hydrophilicity, while local hydrophobic forces enable the grafted layer to sense and attract the hydrophobic domains of protein molecules dissolved in the aqueous environment. The hydrophobic interactions between the material and a hydrophobic probe are investigated using atomic force microscopy measurements and a long-range attractive and contact-adhesive interaction between the material and the probe is observed, which is controlled by environmental conditions. Switching of the layer exterior is also confirmed via protein adsorption measurements. [source]

Bioinspired Design of Dynamic Materials

ADVANCED MATERIALS, Issue 23 2009
Javeed Shaikh Mohammed
Abstract An emerging approach for design of dynamic materials involves mimicking natural systems, which are adept at changing their structure and function in response to their environment. Biological systems possess a diverse range of dynamic mechanisms, including competitive ligand,protein binding, enzyme-catalyzed remodeling, and allosteric protein conformational changes. These dynamic mechanisms are now being exploited by materials scientists and engineers to design "bioinspired" synthetic materials that undergo responsive assembly and disassembly as well as dynamic volume and shape changes. The purpose of this review is to describe recent progress in design and development of bioinspired dynamic materials, with a particular emphasis on hydrogel networks. We specifically focus on emerging approaches that use biological phenomena as an inspiration for design of materials. [source]

Changing concepts of bladder regeneration

INTERNATIONAL JOURNAL OF UROLOGY, Issue 8 2007
Akihiro Kanematsu
Abstract: During the last decade, there has been a dramatic increase in studies aimed at regeneration of the urinary bladder. Many studies employed animal-derived or synthetic materials as grafts for experimental bladder augmentation models, with or without additional measures to promote regeneration, such as autologous cell transplantation or growth factor loading. However, in spite of encouraging results in several reports, few methodologies have shown proven definitive clinical utility. One major problem in these studies is the lack of a clear distinction between native and regenerated bladder in total bladder function after augmentation. Another crucial problem is the absorption and shrinkage of larger grafts, which may result from insufficient vascular supply and smooth muscle regeneration. In contrast, researchers have recently attempted to establish alternative regenerative strategies for treating bladder diseases, and have employed far more diverse approaches according to the various pathological conditions to be treated. For total replacement of the bladder after cystectomy for invasive bladder cancer, urothelium-covered neobladder with non-urinary tract backbone remains a viable choice. In addition, functional bladder diseases such as urinary incontinence, weak detrusor, or non-compliant fibrotic bladder have also been major targets for many leading research groups in this field. These conditions are studied much more from different therapeutic standpoints, aiming at the prevention or reversal of pathological conditions in muscle remodeling or neural control. Such altered research direction would inevitably lead to less surgically based basic biological research, and also would include a far wider spectrum of adult and pediatric bladder diseases, from overactive bladder to dysfunctional voiding. [source]

Comparison of bone-anchored male sling and collagen implant for the treatment of male incontinence

INTERNATIONAL JOURNAL OF UROLOGY, Issue 9 2006
RAHMI ONUR
Aim: To compare the effectiveness of transurethral collagen injection and perineal bone-anchored male sling for the treatment of male stress urinary incontinence (SUI). Methods: Seventy-one men with SUI underwent either transurethral collagen injections (n = 34) or perineal bone-anchored male sling (n = 37) between June 1999 and October 2003. Most of the patients in each group had radical retropubic prostatectomy and/or external beam radiation therapy (EBRT) in relation to the cause of incontinence. There was one patient in both groups who only had EBRT for the cause. The mean duration of incontinence were 4.2 and 4.4 years, respectively. Collagen injections were carried out transurethrally either under regional or general anesthesia until co-aptation of mucosa was observed. The male sling was placed under spinal anesthesia with a bone drill using either absorbable or synthetic materials. Retrospectively, all patients were assessed for continence status and procedure-related morbidity, if present. The outcome of both procedures was also compared with the degree of incontinence. Results: Ten (30%) patients in the collagen group showed either significant improvement or were cured following injections. Preoperatively, the mean pad use in collagen group was 4.5 (SD 2.8) per day, whereas it was 2.2 (SD 1.1) after the injection(s). Collagen injection failed in 24 (70%) of the patients. Patients who received the male sling had a mean preoperative pad use of 3.7 (SD 1.5) and postoperatively, the number decreased to 1.6 (SD 1.2). Most of the patients in this group were either totally dry or significantly improved (n: 28, 76%). There was a statistically significant difference between two groups in respect to success rate (P < 0.05). Analysis of treatment outcome with the degree of incontinence revealed that the male sling is most effective in patients with minimal-to-moderate incontinence. Conclusions: Our results suggest that the male sling, a minimally invasive procedure, is more effective than collagen implant in the treatment of mild-to-moderate SUI in men. [source]

Scanning texture analysis of lamellar bone using microbeam synchrotron X-ray radiation

JOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 1 2007
Wolfgang Wagermaier
Texture analysis with microbeam scanning diffraction enables the local mapping of three-dimensional crystallite orientation in heterogeneous natural and synthetic materials. Cortical (compact) bone is an example of a hierarchically structured biocomposite, which is built mainly of cylindrical osteons, having a lamellar texture at the micrometre level. In this work, a combination of microbeam synchrotron X-ray texture analysis with thin sections of osteonal bone is used to measure the three-dimensional distribution of the c -axis orientation of the mineral apatite in bone with positional resolution of 1,µm. The data reduction procedure needed to go from the stereographic projection of X-ray intensity to the determination of the local orientation of mineralized collagen fibrils is described. The procedure can be applied to other mineralized tissues (such as trabecular bone and chitin) with micrometre scale and biologically controlled fibrillar texture. [source]

Synthesis and characterization of injectable bioadhesive hydrogels for nucleus pulposus replacement and repair of the damaged intervertebral disc

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2010
J. Vernengo
Abstract Bioadhesive polymers are natural or synthetic materials that can be used for soft tissue repair. The aim of this investigation was to develop an injectable, bioadhesive hydrogel with the potential to serve as a synthetic replacement for the nucleus pulposus of the intervertebral disc or as an annulus closure material. Branched copolymers of poly(N -isopropylacrylamide) (PNIPAAm) and poly(ethylene glycol) (PEG) were blended with poly(ethylene imine) (PEI). This three component injectable system can form a precipitated gel at physiological temperature due to the phase transition of PNIPAAm. The injection of glutaraldehyde into the gel core will adhere the implant to the surrounding tissues. 1H NMR results indicated the successful physical incorporation of PEI into the PNIPAAm-PEG network by blending. In addition, the covalent crosslinking between the amine functionalities on the PEI and the aldehyde functionalities on the glutaraldehyde was verified using FTIR difference spectroscopy. Mechanical characterization of these blends showed a significant increase (p < 0.05) in compressive modulus following glutaraldehyde injection. The in vitro bioadhesive force studies with porcine skin showed a significant increase (p < 0.05) in the mean maximum force of detachment for PNIPAAm-PEG/PEI gels when glutaraldehyde was injected into the gel core. The results of this study indicate that the reactivity between amines and aldehyde functionalities can be exploited to impart bioadhesive properties to PNIPAAm-PEG/PEI copolymers. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010 [source]

Maxillary Sinus Elevation Surgery: An Overview

JOURNAL OF ESTHETIC AND RESTORATIVE DENTISTRY, Issue 5 2003
ELIAZ KAUFMAN DDS
ABSTRACT Maxillary sinus elevation surgery was developed to increase the height of bone available for implant placement in the posterior maxilla. The efficacy and predictability of this procedure have been determined in numerous studies. The basic approach to the sinus (Caldwell-Luc operation) involves an osteotomy performed on the lateral maxillary wall, elevation of the sinus membrane, and placement of bone graft material. The graft materials can be categorized into four groups: autogenous bone, allografts (harvested from human cadavers), alloplasts (synthetic materials), and xenografts (grafts from a nonhuman species). These graft materials can be used alone or in combination with each other. Implant placement can occur at the same surgical procedure (immediate placement) or following a healing period of 6 to 9 months (delayed placement). A more conservative approach to the sinus, the osteotome technique, has been described as well. CLINICAL SIGNIFICANCE This article provides an overview of the surgical technique, with emphasis on anatomic considerations, preoperative patient evaluation (clinical and radiographic), indications and contraindications to the procedure, and possible risks and complications. [source]

Nickel-Ion-Mediated Control of the Stoichiometry of His-Tagged Protein/Nanoparticle Interactions

MACROMOLECULAR BIOSCIENCE, Issue 2 2009
Mrinmoy De
Abstract The interaction between synthetic materials and biomolecules plays an important role in biomedical and pathological sciences. An important issue in these interactions is control of stoichiometry. The interaction between NTA ligands and proteins with six consecutive His residues has been widely used for protein purification. Control of stoichiometry is an important issue in applying this recognition strategy to the creation of defined nanoparticle-protein conjugates. In this communication we report the direct control of particle-protein stoichiometry through variation of nickel chloride concentration, as demonstrated through fluorescence and gel electrophoresis. [source]

Corrosion aspects of metallic implants , An overview

MATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 11 2008
A. Balamurugan
Abstract The ability to replace or augment diseased body parts totally or partially has improved both the quality and life span of human population. The decline in surgical risks during recent decades has encouraged the development of more complex procedures for prosthetic implantation. Additionally, a variety of extracorporeal devices, such as the heart, lung and blood dialysis machines are used routinely, but these prosthetic elements have several limitations. Hence, research projects are currently underway to overcome the limitations of synthetic materials by developing formulations with varying properties, such as asymptomatic, long-term function in the human physiological environment, etc., to meet the needs of biomedical surgeons. This review focuses on the several biomaterials corrosion and its measures to prevent corrosion. [source]

Characterization of a novel bioactive poly[(lactic acid)- co -(glycolic acid)] and collagen hybrid matrix for dermal regeneration

POLYMER INTERNATIONAL, Issue 10 2005
Kee Woei Ng
Abstract Different strategies have been explored for the purpose of autologous or allogeneic dermal regeneration. We have developed a hybrid matrix by lyophilizing collagen within a poly[(lactic acid) -co -(glycolic acid)] (10:90, molar composition) knitted mesh, in order to assimilate the advantages of natural and synthetic materials. The porosity of the mesh was found to be almost 95 %, using Micro-Computed Tomography Analysis, while the mechanical properties were comparable to native skin. In vitro biocompatibility was analyzed by culturing rat dermal fibroblasts in the matrices over 10 days. The cells were able to attach, proliferate and remain viable within the hybrid matrices. Subsequently, in vivo biocompatibility was analyzed by implanting the matrices subcutaneously in immunocompetent rats, for 2 weeks. Histological analysis showed that the poly[(lactic acid) -co -(glycolic acid)],collagen hybrid matrices evoked minimal host tissue response in vivo. This study forms the basis of using poly[(lactic acid) -co -(glycolic acid)],collagen hybrid matrices for our future work to develop a bioactive matrix for dermal regeneration. Copyright © 2005 Society of Chemical Industry [source]

Biopolymere in textilen Anwendungen.

CHEMIE IN UNSERER ZEIT (CHIUZ), Issue 3 2009
Polyhydroxyalkanoate, Polylactid
Abstract Biopolymere stellen eine interessante Polymerklasse dar, deren Potential bisher noch nicht endgültig erfasst ist. Sie gewinnen jedoch zunehmend an Marktwert. Vor allem Polylactid (PLA) hat sich bereits durchsetzen können, da es nicht nur aus nachwachsenden Rohstoffen hergestellt werden kann und abbaubar ist, sondern darüber hinaus ein Eigenschaftsprofil aufweist, das mit herkömmlichen thermoplastischen Kunststoffen vergleichbar ist und sich auch ähnlich gut verarbeiten lässt. Das Anwendungsfeld der Biopolymere reicht von Folien, Obst- und Gemüseschalen bis hin zu Hygiene- und Medizinartikeln und ist daher sehr vielfältig. Diese Vielfältigkeit wird sicherlich in der Zukunft weiter zunehmen. Biopolymers represent an interesting class of polymers whose potential is not yet been fully realised. However, more recently, biopolymers are gaining impetus in the market. Among the biopolymers, polylactic acid (PLA) is being used successfully and is widely accepted because it is produced from natural raw material and is degradable. Furthermore, it has comparable properties to standard thermoplastic polymers and can also be processed using similar process channels as conventional thermoplastic synthetic materials. Biopolymer applications are manifold and range from foils, fruit and vegetable packaging to hygiene and medical products. It can be expected that in future the application spectrum of biopolymers will increase even further. [source]

Orthogonally Self-Assembled Multifunctional Block Copolymers

CHEMISTRY - A EUROPEAN JOURNAL, Issue 44 2009
Ashootosh
Abstract We report the synthesis of telechelic poly(norbornene) and poly(cyclooctene) homopolymers by ring-opening metathesis polymerization (ROMP) and their subsequent functionalization and block copolymer formation based on noncovalent interactions. Whereas all the poly(norbornene)s contain either a metal complex or a hydrogen-bonding moiety along the polymer side-chains, together with a single hydrogen-bonding-based molecular recognition moiety at one terminal end of the polymer chain. These homopolymers allow for the formation of side-chain-functionalized AB and ABA block copolymers through self-assembly. The orthogonal natures of all side- and main-chain self-assembly events were demonstrated by 1H,NMR spectroscopy and isothermal titration calorimetry. The resulting fully functionalized block copolymers are the first copolymers combining both side- and main-chain self-assembly, thereby providing a high degree of control over copolymer functionalization and architecture and bringing synthetic materials one step closer to the dynamic self-assembly structures found in nature. [source]

Theoretical Study of Catalytic Efficiency of a Diels,Alderase Catalytic Antibody: An Indirect Effect Produced During the Maturation Process

CHEMISTRY - A EUROPEAN JOURNAL, Issue 2 2008
Sergio Martí Dr.
Abstract The Diels,Alder reaction is one of the most important and versatile transformations available to organic chemists for the construction of complex natural products, therapeutics agents, and synthetic materials. Given the lack of efficient enzymes capable of catalyzing this kind of reaction, it is of interest to ask whether a biological catalyst could be designed from an antibody-combining site. In the present work, a theoretical study of the different behavior of a germline catalytic antibody (CA) and its matured form, 39,A-11, that catalyze a Diels,Alder reaction has been carried out. A free-energy perturbation technique based on a hybrid quantum-mechanics/molecular-mechanics scheme, together with internal energy minimizations, has allowed free-energy profiles to be obtained for both CAs. The profiles show a smaller barrier for the matured form, which is in agreement with the experimental observation. Free-energy profiles were obtained with this methodology, thereby avoiding the much more demanding two-dimensional calculations of the energy surfaces that are normally required to study this kind of reaction. Structural analysis and energy evaluations of substrate,protein interactions have been performed from averaged structures, which allows understanding of how the single mutations carried out during the maturation process can be responsible for the observed fourfold enhancement of the catalytic rate constant. The conclusion is that the mutation effect in this studied germline CA produces a complex indirect effect through coupled movements of the backbone of the protein and the substrate. [source]