Publications by authors named "Alexander Bollinger"

Engineering dual-function single polypeptide catalysts with two abiotic or biotic catalytic entities (or combinations of both) supporting cascade reactions is becoming an important area of enzyme engineering and catalysis. Herein we present the development of a PluriZyme, TR E , with efficient native transaminase (k : 69.49±1.

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Bacterial lipolytic enzymes of family IV are homologs of the mammalian hormone-sensitive lipases (HSL) and have been successfully used for various biotechnological applications. The broad substrate specificity and ability for enantio-, regio-, and stereoselective hydrolysis are remarkable features of enzymes from this class. Many crystal structures are available for esterases and lipases, but structures of enzyme-substrate or enzyme-inhibitor complexes are less frequent although important to understand the molecular basis of enzyme-substrate interaction and to rationalize biochemical enzyme characteristics.

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Biodegradation of synthetic polymers, in particular polyethylene terephthalate (PET), is of great importance, since environmental pollution with PET and other plastics has become a severe global problem. Here, we report on the polyester degrading ability of a novel carboxylic ester hydrolase identified in the genome of the marine hydrocarbonoclastic bacterium VGXO14 . The enzyme, designated PE-H, belongs to the type IIa family of PET hydrolytic enzymes as indicated by amino acid sequence homology.

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Biocatalysis has emerged as an important tool in synthetic organic chemistry enabling the chemical industry to execute reactions with high regio- or enantioselectivity and under usually mild reaction conditions while avoiding toxic waste. Target substrates and products of reactions catalyzed by carboxylic ester hydrolases are often poorly water soluble and require organic solvents, whereas enzymes are evolved by nature to be active in cells, i.e.

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Biosurfactants are amphiphilic secondary metabolites produced by microorganisms. Marine bacteria have recently emerged as a rich source for these natural products which exhibit surface-active properties, making them useful for diverse applications such as detergents, wetting and foaming agents, solubilisers, emulsifiers and dispersants. Although precise structural data are often lacking, the already available information deduced from biochemical analyses and genome sequences of marine microbes indicates a high structural diversity including a broad spectrum of fatty acid derivatives, lipoamino acids, lipopeptides and glycolipids.

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Hydrolases acting on polyesters like cutin, polycaprolactone or polyethylene terephthalate (PET) are of interest for several biotechnological applications like waste treatment, biocatalysis and sustainable polymer modifications. Recent studies suggest that a large variety of such enzymes are still to be identified and explored in a variety of microorganisms, including bacteria of the genus Pseudomonas. For activity-based screening, methods have been established using agar plates which contain nanoparticles of polycaprolactone or PET prepared by solvent precipitation and evaporation.

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Amination of bulky ketones, particularly in () configuration, is an attractive chemical conversion; however, known ω-transaminases (ω-TAs) show insufficient levels of performance. By applying two screening methods, we discovered 10 amine transaminases from the class III ω-TA family that were 38% to 76% identical to homologues. We present examples of such enzymes preferring bulky ketones over keto acids and aldehydes with stringent () selectivity.

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Marine habitats represent a prolific source for molecules of biotechnological interest. In particular, marine bacteria have attracted attention and were successfully exploited for industrial applications. Recently, a group of Pseudomonas species isolated from extreme habitats or living in association with algae or sponges were clustered in the newly established Pseudomonas pertucinogena lineage.

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Esterases receive special attention because of their wide distribution in biological systems and environments and their importance for physiology and chemical synthesis. The prediction of esterases' substrate promiscuity level from sequence data and the molecular reasons why certain such enzymes are more promiscuous than others remain to be elucidated. This limits the surveillance of the sequence space for esterases potentially leading to new versatile biocatalysts and new insights into their role in cellular function.

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The Gram-negative proteobacterium DSM 1045 is considered a promising source for enzymes of biotechnological interest, e.g., hydrolases and transaminases.

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Case: We report a case of catastrophic implant failure due to fatigue fracture of a well-functioning unicompartmental knee arthroplasty at 7 years in an active 55-year-old man, who presented with sudden onset of atraumatic knee pain and effusion. The patient underwent revision to total knee arthroplasty. Intraoperative findings included a metallic fragment fractured off the rim of the tibial base-plate and cement retained in the tibial tray.

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Background: Hip fractures have significant effects on the geriatric population and the health care system. Prior studies have demonstrated both the safety of intravenous (IV) acetaminophen and its efficacy in decreasing perioperative narcotic consumption. The purpose of this study is to evaluate the effect of scheduled IV acetaminophen for perioperative pain control on length of hospital stay, pain level, narcotic use, rate of missed physical therapy (PT) sessions, adverse effects, and discharge disposition in geriatric patients with hip fractures.

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Purpose: To identify factors and attributes hand surgery fellowship program directors consider important in selecting applicants for interview and ranking.

Methods: A web-based questionnaire was sent to all hand fellowship program directors in the United States. The questionnaire was designed to identify the most important criteria in granting an interview, sources of letters of recommendation, the interview process, and factors used to rank a candidate.

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Objective: Supraspinatus tendon trauma may contribute to residual shoulder pain after nail fixation for proximal humeral fractures. Some have proposed a more medial starting point for humeral nail insertion to avoid cuff tendon footprint damage. We hypothesized that percutaneous nail insertion via Neviaser portal would not only be possible, but would avoid tendon trauma, while sacrificing articular cartilage.

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Biomaterial wear debris is a known contributing factor in aseptic loosening of total joint prostheses, particularly when cementless tibial trays are used in total knee arthroplasty (TKA). Local inflammatory response can lead to osteolysis and aseptic loosening of implants. The resulting lesions require careful clinical evaluation.

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