Chipens G I, Afanasjeva G A, Ancan Y E, Zalitis G M, Vegner R E, Balodis Y Y
Biokhimiia. 1978 May;43(5):872-9.
The antigen activity of angiotensin, its fragments and analogues, which contain enantiomeric forms of amino acids and aza-alpha'-homoamino acids is studied by cross reactions with specific antibodies, obtained for angiotensin and its central tetrapeptide. It is found that the inclusion of additional NH-group between alpha carbon and carboxyl group of peptide chain, although in few cases radically changes spatial structure of compounds, does not deprivate their antigen activity. The replacement of NH-group to the C-end of the angiotensin molecule by affection the antigen determinant considerably decreases the antigen activity of the analogues. The important role in the determination of the antigen activity play the tyrosine residue and its specific orientation with respect to the antigen molecule. Low molecular weight fragments and analogues of the central part of angiotensin molecule, which have less "rigid" spatial structures, are capable to reorganize their spatial structure during interaction with antibodies.
通过与针对血管紧张素及其中心四肽获得的特异性抗体进行交叉反应，研究了血管紧张素及其片段和类似物（其中包含氨基酸的对映体形式和氮杂-α'-高氨基酸）的抗原活性。研究发现，尽管在少数情况下肽链的α碳原子和羧基之间额外的NH基团会从根本上改变化合物的空间结构，但并不会使其丧失抗原活性。通过影响抗原决定簇，将血管紧张素分子C端的NH基团替换会显著降低类似物的抗原活性。酪氨酸残基及其相对于抗原分子的特定取向在抗原活性的测定中起着重要作用。血管紧张素分子中心部分具有较不“刚性”空间结构的低分子量片段和类似物，在与抗体相互作用时能够重新组织其空间结构。
