We describe mass spectrometric antibody-peptide binding motif analyses of a monoclonal antibody (clone 18E9.D9, BioLegend, London, England) from mouse which was raised against the predominantly occuring phosphorylated linker sequence HpTGEKP of human C2H2 zinc finger proteins. As the anti-HpTGEKP antibody is assumed to bind to related phosphorylated C2H2 ZNF protein linker sequences as well, specific amino acid exchanges were investigated for evaluating their importance for immune complex formation. Two point mutations of the zinc finger protein 331 (ZNF331) gene, causing single amino acid exchanges R9I and H11Y, respectively, have been found to be significantly enriched in Uterine Corpus Endometrial Carcinoma, Colon and Rectal Adenocarcinomas, and Skin Cutaneous Melanoma. Since the H11Y amino acid exchange affects histidine residue H1 of the HpTGEKP linker motif which is recognized by the anti-HpTGEKP antibody, we examined in this work whether the in several cancers mutated linker amino acid sequence YTGEKP and its phosphorylated derivatives YpTGEKP, pYTGEKP, and pYpTGEKP would be bound by the anti-HpTGEKP antibody. Immune complex formation ability was compared to that of peptides HTGEKP, HpTGEKP, and HpTGKKP, respectively, which served as controls. Binding behaviors towards the anti-HpTGEKP antibody were investigated by "Intact Transmission Epitope Mapping - Thermodynamic Weak-force Order (ITEM-TWO)".