Table 2

MH^+a	Cross-linked β-CN via isopeptide bonds	Q- and K- residue involved in cross-linking	MS experiment
6141.30^b	(⁶⁰LQDKIHPFAQAQSLVYPFTGPIPNSLPQNILPLTQTPVVVPPFLQPE¹⁰⁶) T (¹¹⁶TMVPKHKE¹²³)	(Q₈₇or Q₉₄)- (K₁₂₀or K₁₂₂)	ESI-MS/MS
13688.52^b	(⁶⁰LQDKIHPFAQAQSLVYPFTGPIPNSLPQNILPLTQTPVVVPPFLQPE¹⁰⁶) T (¹⁴⁷KLHLPLPLVQSWMHQPPQPLPPTVMFPPQSVLSLSQPKVLPVPQKAVPQRDMPIQAFLLYQEPVLGPVRGPFPILV²²²)	(Q₇₁or Q94)- (K₁₂₀ or K₁₂₂)	ESI-MS/MS
2606.47^d	(⁶⁸AQAQSLVYPF77)T(¹⁹¹KAVPQRDMPIQAF²⁰³)	(Q₇₁)-(K₁₉₁)	LC-ESI-MS
3034.62^d	(⁹³TQTPVVVPPFLQPE¹⁰⁶)T(¹⁹¹KAVPQRDMPIQAF²⁰³)	(Q₉₄)-(K₁₉₁)	LC-ESI-MS

Table 2:
^a MH+ values observed by MALDI-TOF MS; Peptide generated from:
^bGlu-C hydrolysis of polymer b-CN at 4-h incubation time;
^cchymotryptic cleavage of peptide at MH+ 6141.30;
^dchymotryptic cleavage of peptide at MH+ 13668.52. Numbers indicate the amino acid residues at the extremities of each peptide refers to b-CN (P11839). Transamidated Q- and K-residues are indicated in bold.