Gregorio Weber (July 4, 1916– July 18, 1997) was an Argentinian scientist who made significant contributions to the fields of fluorescence spectroscopy and protein chemistry. Weber was elected to the National Academy of Sciences in 1975.
Early Life and Education
Gregorio Weber was born in Buenos Aires, Argentina in 1917. He attended the University of Buenos Aires where he received his Doctor of Medicine degree in 1942. Weber continued his studies at the University of Cambridge under the guidance of Malcolm Dixon and, in 1947, earned a Ph.D. in biochemistry. His thesis, titled "Fluorescence of Riboflavin, Diaphorase and Related Substances", marked the beginning of the application of fluorescence spectroscopy to biomolecules.
Gregorio Weber is acknowledged to be the person responsible for many of the more important theoretical and experimental developments in modern fluorescence spectroscopy. In particular, Weber pioneered the application of fluorescence spectroscopy to the biological sciences. His list of achievements includes: the synthesis and use of dansyl chloride as a probe of protein hydrodynamics; the extension of Perrin’s theory of fluorescence polarization to fluorophores associated with random orientations with ellipsoids of revolution and to mixtures of fluorophores; the first spectral resolution of the fluorescence of the aromatic amino acids and of intrinsic fluorescence of proteins; the first demonstration that both FAD and NADH make internal complexes; the first report on aromatic secondary amines, which are strongly fluorescent in apolar solvents, but hardly in water, the most spectacular case being the anilino naphthalene sulfonates (ANS); the first description of the use of the fluorescence of small molecules as probes for the viscosity of micelles, with implications for membrane systems; a general formulation of depolarization by energy transfer; the discovery of the “red-edge” effect in homo-energy transfer; the development of modern cross-correlation phase fluorometry; the development of the excitation-emission matrix method for resolving contributions from multiple fluorophores; the synthesis of several novel fluorophores, including pyrenebutyric acid, IAEDANS, bis-ANS, PRODAN and LAURDAN, designed to probe dynamic aspects of biomolecules. In addition to these seminal contributions, Gregorio Weber also trained and inspired generations of spectroscopists and biophysicists who went on to make important contributions to their fields, including both basic research as well as the commercialization of fluorescence methodologies and their extension into the clinical and biomedical disciplines.
Gregorio Weber’s original and life-long motivation was to use fluorescence methods to probe the nature of proteins and in addition to his contributions to the fluorescence field, he was one of the true pioneers of protein dynamics. A study of his papers from the 1960's demonstrates that even then he regarded proteins as highly dynamic molecules. He rejected the view, common at that time after the appearance of the first x-ray structures, that proteins had a unique and rigid conformation. In an important innovation, he introduced the use of molecular oxygen to quench fluorescence in aqueous solutions, which led to the detection, for the first time and to the surprise of many, of the existence of fast fluctuations in protein structures on the nanosecond time scale. The impact of this work was shown by the increasing interest in experimental and theoretical work in protein dynamics, which followed. Weber’s early description of proteins in solution as “kicking and screaming stochastic molecules” has, in recent years, been fully verified both from theoretical and experimental studies. These contributions were recognized by the American Chemical Society in 1986, which named Weber as the first recipient of Repligen Award for the Chemistry of Biological Processes. In the 1970's, initially in collaboration with H.G. Drickamer, Weber combined fluorescence and hydrostatic pressure methods to the study of molecular complexes and proteins. It is interesting to note that the initial system he thought to study was the complex formed by isoalloxazine and adenine, one of his original research interests. These observations confirmed the applicability of fluorescence and high-pressure techniques to problems of structure, and particularly dynamics, at the molecular level. Weber and collaborators demonstrated that most proteins made up of subunits can be dissociated by the application of hydrostatic pressure, and opened, in this way, a new method to study protein-protein interactions. In these studies, quite unexpected properties of protein aggregates were revealed and a new approach to problems in biology and medicine was opened by these observations. For example, Weber and his collaborators demonstrated the possibility of destroying the infectivity of viruses, without affecting their immunogenic capacity, by subjecting them to hydrostatic pressure, and thus opened the possibility of developing viral vaccines that contain, without covalent modification, all the antigens present in the original virus.
- "Biophysical Journal, Volume 75, July 1998, pages 419-421"
- Gregorio Weber at the University of California, Irvine
- Tributes to Gregorio Weber at Cardiff University
- Publications by Gregorio Weber at the Laboratory for Fluorescence Dynamics