An improved procedure, involving mass spectrometry, for N-terminal amino acid sequence determination of proteins which are N alpha-blocked.
A modification to a previously described procedure [Gray & del Valle (1970) Biochemistry 9, 2134-2137; Rose, Simona & Offord (1983) Biochem. J. 215, 261-272] for mass-spectral identification of the N-terminal regions of proteins is shown to be useful in cases where the N-terminus is blocked. Three proteins were studied: vesicular-stomatitis-virus N protein, Sendai-virus NP protein, and a rabbit immunoglobulin lambda-light chain. These proteins, found to be blocked at the N-terminus with either the acetyl group or a pyroglutamic acid residue, had all failed to yield to attempted Edman degradation, in one case even after attempted enzymic removal of the pyroglutamic acid residue. The N-terminal regions of all three proteins were sequenced by using the new procedure.
D000595:Amino Acid Sequence; D007146:Immunoglobulin lambda-Chains; D013058:Mass Spectrometry; D008722:Methods; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D011506:Proteins; D014758:Viral Core Proteins; D014764:Viral Proteins
D007146:Immunoglobulin lambda-Chains; D019590:Nucleocapsid Proteins; D009698:Nucleoproteins; D011506:Proteins; D014758:Viral Core Proteins; D014764:Viral Proteins