A previously described technique [Rose, Simona, Offord, Prior, Otto & Thatcher (1983) Biochem. J. 215, 273-277] permits the identification of the C-terminal peptide of a protein as the only peptide that does not incorporate any 18O upon partial enzymic hydrolysis in 18O-labelled water. Formation of chemical derivatives followed by combined g.l.c.-m.s. was used in this earlier work. We now descr...

14. Barber, M., Bordoli, R. S., Sedgwick, R. D. & ‘lylcr, A. N . ( 198 I ) J. Chem. Soc. Chem. Commirri. 7,325-327 Biemann, K. & Martin, S. A. ( 1 987) Moss Spectrom. Rev. 6 , 1-76 Gibson, B. W. & Biemann, K. (1984) /’roc. Nor/. Aciid. Sci. U.S.A. 8 I , 1956I960 Allmaier, G., Chao, B. H., Khorana, H. G. & Biemann, K. ( 1986) in Annual Conference on Moss Spectrometty w i r l Allied Topics 34h, p...

In order to resolve the uncertainties about the primary structure of human myelin basic protein at residues 45-89, the sequence of this peptide and its tryptic fragments were reinvestigated by fast atom bombardment mass spectrometry. The sequence at positions 77-78 was found to be His-Gly and the sequence at positions 83-84 was shown to be Glu-Asn. The Ser at position 56 was not phosphorylated,...

Nitrogenase in Rhodospirillum rubrum is inactivated in vivo by the covalent modification of the Fe protein with a nucleotide. The preparation of two modified peptides derived from proteolytic digestion of the inactive Fe protein is described. The modifying group is shown to be adenosine diphosphoribose, linked through the terminal ribose to a guanidino nitrogen of arginine. The structural featu...

Protein structural fluctuation, typically measured by Debye-Waller factors, or B-factors, is a manifestation of protein flexibility, which strongly correlates to protein function. The flexibility-rigidity index (FRI) is a newly proposed method for the construction of atomic rigidity functions required in the theory of continuum elasticity with atomic rigidity, which is a new multiscale formalis...

A new approach using fast atom bombardment combined with mass spectrometry to characterize polycyclic aromatic hydrocarbons (PAHs) in the range of 128-252 u molecular weight is described. Sulfolane was employed as a liquid matrix for these π-conjugated hydrocarbons. Bombardment of sulfolane solution of certain PAHs with an atom beam produces both radical cation (M(+.)) and protonated molecule [...