Investigation of protein‐protein noncovalent interactions in soybean agglutinin by electrospray ionization time‐of‐flight mass spectrometry

Xue‐Jun ‐J Tang, C. Fred Brewer, Sanat Saha, Igor Chernushevich, Werner Ens, Kenneth G. Standing, Brian T. Chait

Research output: Contribution to journalArticle

59 Scopus citations


Noncovalent interactions in soybean agglutinin (SBA) were studied on an electrospray ionization (ESI) time‐of‐flight mass spectrometer constructed recently at the University of Manitoba. The high m/z range and high sensitivity of the instrument together with mild ESI interface conditions turned out to be ideal for detecting this noncovalently bonded tetrameric protein (MW ∼ 116 000 Da) in low charge states (z=23 to 27). By altering the acetonitrile content of the SBA solutions it was shown that the observed SBA tetramers are due to structurally specific noncovalent associations in solution. Octamers and dodecamers (MW ∼ 350 000 Da) were also detected. Information on the quaternary structure of the tetramers was obtained by analyzing the fragment‐ion spectrum resulting from the collision‐induced dissociation of the tetramer ions.

Original languageEnglish (US)
Pages (from-to)750-754
Number of pages5
JournalRapid Communications in Mass Spectrometry
Issue number9
Publication statusPublished - Sep 1994


ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry

Cite this