Cooper H M, East I J, Todd P E, Leach S J
Mol Immunol. 1984 Jun;21(6):479-87. doi: 10.1016/0161-5890(84)90063-4.
Using both direct and competitive binding studies it is demonstrated that antibodies to beef myoglobin raised in sheep are able to distinguish between beef and sheep myoglobins although these two proteins differ by only six of the 153 amino acid residues. By contrast, antibodies to beef myoglobin raised in rabbits, dogs and chickens bind almost equally well to beef and sheep myoglobins. It is also shown that antibodies to beef myoglobin raised in sheep have a lower avidity for beef myoglobin than do antibodies raised in more distantly related species. Furthermore, only 50% of the specific anti-beef myoglobin antibodies isolated from sheep antisera will bind to sheep myoglobins whereas 100% of the specific antibodies isolated from the antisera of the other immunised species will bind to sheep myoglobin. It is suggested that antibodies to beef myoglobin are raised to those surface regions which are topographically altered as a result of sequence differences from the host's own myoglobin. When the host animal is evolutionarily distant these sequence differences are considerable and antibodies are raised to the entire surface of the molecule. However, when the host's myoglobin is very similar in sequence to beef myoglobin (as is the case when using sheep as the host animal) antibodies are made only to surface regions affected by the sequence differences. Some of these antibodies--those to the regions of greatest difference--will bind weakly if at all to sheep myoglobin, while those directed to areas of lesser difference will bind well to sheep myoglobin.
通过直接结合研究和竞争性结合研究均表明，在绵羊体内产生的抗牛肉肌红蛋白抗体能够区分牛肉肌红蛋白和绵羊肌红蛋白，尽管这两种蛋白质在153个氨基酸残基中仅有6个不同。相比之下，在兔子、狗和鸡体内产生的抗牛肉肌红蛋白抗体与牛肉肌红蛋白和绵羊肌红蛋白的结合几乎同样良好。研究还表明，在绵羊体内产生的抗牛肉肌红蛋白抗体对牛肉肌红蛋白的亲和力低于在亲缘关系更远的物种体内产生的抗体。此外，从绵羊抗血清中分离出的特异性抗牛肉肌红蛋白抗体只有50%能与绵羊肌红蛋白结合，而从其他免疫物种的抗血清中分离出的特异性抗体则有100%能与绵羊肌红蛋白结合。有人提出，抗牛肉肌红蛋白抗体是针对那些由于与宿主自身肌红蛋白的序列差异而在拓扑结构上发生改变的表面区域产生的。当宿主动物在进化上距离较远时，这些序列差异相当大，抗体是针对分子的整个表面产生的。然而，当宿主的肌红蛋白在序列上与牛肉肌红蛋白非常相似时（如以绵羊作为宿主动物的情况），抗体仅针对受序列差异影响的表面区域产生。其中一些抗体——针对差异最大区域的抗体——如果能与绵羊肌红蛋白结合的话也会很弱，而针对差异较小区域的抗体则能与绵羊肌红蛋白很好地结合。
