Year: 2011
Type: other
Abstract: Jim Brown, a pioneer in the art of sequencing proteins in the pre-DNA era, has died at the age of 80. Jim received his Ph.D. at the University of Washington under the tutelage of Hans Neurath at a time when Seattle was the hub of the protease world for determining the structural and mechanistic basis of catalysis, structure, and mechanism.From there, Brown went to Cambridge (England) for postdoctoral work with Brian Hartley, where he worked on porcine elastase, the sequence of which provided more raw materials for an insightful Nature paper in 1965 on the evolution of serine proteases.However, it was an ingenious method for assigning disulfide bonds that heralded Jim's first major triumph.The medium of the day in protein sequencing was Whatman 3M filter paper, squares or strips of which were used for paper chromatography or electrophoresis or combinations of the two.Vernon Ingram had introduced two-dimensional ''fingerprints'' for separating peptide fragments after a protein was digested by various means, electrophoresis being conducted in one dimension and chromatography in other.Other workers introduced ''diagonal methods'' in which the same conditions were employed in both of two dimensions after turning the paper 90 , some chemical or enzymatic modification being conducted in the interval that would lead to a predictable change in mobility for some of the peptides.Jim Brown took the procedure to a new level of sophistication, however, one that allowed the determination of disulfide assignments in large and complex proteins.He did this by subjecting digests separated on paper electrophoresis directly to performic acid vapors, thereby oxidizing every disulfide to a pair of negatively charged cysteic acids.Typically, a pepsin
Source: Protein Science
DOI: 10.1002/pro.694
Author: Russell Doolittle
Institution: University of California System
Language: English
Subfield: History
Field: Arts and Humanities
Domain: Social Sciences
Open Access status: bronze
OpenAlex ID: W1986465595