Binding constants for complexes of α-cyclodextrin with l-phenylalanine and some related substrates

Owen Fennema: Food Chemist Extraordinaire

Periodically someone comes into a field and forces a change in direction, a paradigm shift. Owen Fennema was such a person in food science and technology. When he started his academic career, curricula in food science and technology had courses describing how to process plant produce and animal tissue into safer food with an extended shelf life. The "why" was often overlooked. Owen changed all that. He participated in and greatly contributed to a paradigm shift in teaching food science by editing one of the most important textbook series in food science and technology. In addition, his research on water and ice as they impacted the chemical, physical, and biological characteristics of plant and animal tissues extended the bounds of knowledge. He did the same for edible bilayers with research done in his laboratory. Who was this man, and how could he have such impact? Hopefully, this review provides some insights into Owen Fennema, Renaissance man.

Recombinamers: combining molecular complexity with diverse bioactivities for advanced biomedical and biotechnological applications

The rapid development of polymer science has led to literally thousands of different monomers and an almost endless number of possibilities arising from their combination. The most promising strategy to date has been to consider natural products as macromolecules that provide the best option for obtaining functional materials. Proteins, with their high levels of complexity and functionality, are one of the best examples of this approach. In addition, the development of genetic engineering has permitted the design and highly controlled synthesis of proteinaceous materials with complex and advanced functionalities. Elastin-like recombinamers (ELRs) are presented herein as an example of an extraordinary convergence of different properties that is not found in any other synthetic polymer system. These materials are highly biocompatible, stimuli-responsive, show unusual self-assembly properties, and can incorporate bioactive domains and other functionalities along the polypeptide chain. These attributes are an important factor in the development of biomedical and biotechnological applications such as tissue engineering, drug delivery, purification of recombinant proteins, biosensors or stimuli-responsive surfaces.

Smart Elastin-like Polymers

Elastin-like polymers are a new family of proteinaceous polymers. In these polymers converge a wide set of interesting properties that difficultly can be found together in other polymers. They are extremely biocompatible and show an acute smart and self-assembling behaviour. The increasing in complexity of the molecular design renders polymers showing combination of functionalities and complex performance. This is specially true nowadays where, taking into account their peptide nature, these polymers can be produced as recombinant proteins in genetically modified (micro)organisms. The absolute control and absence of randomness in the primary structure makes possible the realization of multifunctional polymers that can combine physical, chemical and biological functions in a desired fashion. It can be said that the molecular design is mainly limited by imagination and not by technique. This chapter is intended to show the molecular parameters that explain the smart behaviour finally observed and how the increase in complexity of the molecular designs leads to a richer behaviour of the polymer, as a way to show the enormous potential of this family in the development of advanced materials and systems for biomedicine and nanotechnology for the next decades.

Determination of binding constants of cyclodextrin inclusion complexes with amino acids and dipeptides by potentiometric titration

Cyclodextrins are well known for their ability to separate enantiomers of drugs, natural products, and other chiral substances using HPLC, GC, or CE. The resolution of the enantiomers is due to the formation of diastereomeric complexes between the cyclodextrin and the pairs of enantiomers. The aim of this study was to determine the binding constants of the complexes between alpha- and beta-cyclodextrin and the enantiomers of a series of aliphatic and aromatic amino acids, and dipeptides, using a potentiometric titration method. The results of this method are compared to other methods, and correlated to findings in cyclodextrin-modified capillary electrophoresis and possible complex structures. Potentiometric titration was found to be an appropriate tool to determine the binding constants of cyclodextrin inclusion complexes.