RAPID PROTEIN IDENTIFICATION USING N-TERMINAL SEQUENCE TAG AND AMINO-ACID-ANALYSIS

Proteins can be identified by amino acid analysis and database matchin g, but it is often desirable to increase the confidence in identity th rough the use of other techniques. Here we describe a rapid protein id entification method that uses Edman degradation to create a 3 or 4 ami no acid N-terminal ''sequence tag,'' following which proteins are subj ected to amino acid analysis protein identification procedures. Edman degradation methods have been modified to take only 23 min per cycle, and rapid amino acid analysis techniques are used. The Edman degradati on and amino acid analysis is done on a single PVDF membrane-bound pro tein sample. A computer database matching program is also presented wh ich uses both amino acid composition and ''sequence tag'' data for pro tein identification. This method represents the most inexpensive, accu rate, and rapid means of protein identification, which is ideal for th e screening of proteomes separated by 2-D gel electrophoresis. The cre ation of N-terminal Edman degradation ''sequence rags'' prior to pepti de mass fingerprinting of samples should also be useful. (C) 1996 Acad emic Press. Inc.