Matter P, Davidson F D, Wyckoff R W
Proc Natl Acad Sci U S A. 1969 Nov;64(3):970-2. doi: 10.1073/pnas.64.3.970.
Analyses of the protein residues recovered from fossil oyster shells of ages from the Pleistocene through the Cretaceous show substantially the same amino acids as are present in modern proteins. The amount of these residues declines sharply to the Oligocene, after which it proceeds more slowly. These older proteins contain relatively less aspartic acid and glycine than do their younger counterparts.
对从更新世到白垩纪时期的化石牡蛎壳中回收的蛋白质残留物的分析表明,其氨基酸与现代蛋白质中的氨基酸基本相同。这些残留物的数量在渐新世急剧下降,之后下降速度变慢。与较年轻的蛋白质相比,这些较古老的蛋白质含有的天冬氨酸和甘氨酸相对较少。