1964 Volume 10 Issue 3 Pages 277-281
The B12-complex and several wall preparations with various treatments have been analyzed for the amino acid compositions. The complex consists of lysine 30, threonine 15, valine 10, alanine 7, aspartic acid 7, leucine 7, glycine 5, glutamic acid 4, phenylalanine 4, isoleucine 3, serine 3, tyrosine 3, and vitamin B12 1. The major amino acids of the wall preparations are aspartic acid, glutamic acid, alanine, and lysine with the molar ratio of 1:1.2:2.1:1.2.
The reason of difference of amino acid compositions of the complex and the wall preparations is discussed as a consequence of isolating a minute part of the wall for the binding of B12 which may be specific in the B12-requiring Lactobacillus.