Biochemistry of Amino Acids - A. Meister 1961

Natural Amino Acids
Peptides and Related Compounds
Other Compounds

A crystalline compound related to y-glutamyl Amino Acids, namely β-(N-y-glutamyl)aminopropionitrile, has been isolated from the seeds of Lathyrus odoratus.

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β-(N-y-L-Glutamyl)aminopropionitrile

This compound induces skeletal deformities in rats that are characteristic of lathyrism [428]. Lathyrism is a disorder associated with the consumption of food products derived from certain legumes, including Lathyrus sativus and L. odoratus. It is characterized by The Development of spastic paraplegia, convulsions, Osteoporosis, and skeletal alterations. Administration of the active principle of L. odoratus to rats causes skeletal deformities without causing mortality [429]. Schilling and Strong [428] isolated L-glutamic acid and β-Alanine from acid hydrolysates of the L. odoratus factor and subsequently synthesized the aforementioned nitrile.

The molecule of puromycin, an antibiotic isolated from Streptomyces alboniger, has been found to contain p-methoxyphenyl-L-alanine (p. 59), 6-dimethylaminopurine, and D-3-aminoribose [285]. Serratamic acid, a peptide containing L-Serine and hydroxydecanoic acid, is produced by certain strains of microorganisms belonging to the genus Serratia [430]. The structures of hypertensin [581], ACTH [528], Glucagon [583], and several other naturally occurring Peptides have recently been elucidated [584].

The peptides listed above likely represent only a small fraction of all naturally occurring peptides (see [431, 432]). The so-called "peptide A" has been isolated in a relatively pure state from the Liver of certain animals [433]. Peptides that inhibit The activity of Trypsin and Pepsin have been described [434]. A tissue peptide containing Lysine has been obtained which, much like synthetic polylysine, exhibits antibacterial properties [435]. Spores of certain Bacteria, such as Bacillus subtilis, contain peptides composed of hexosamine residues, a,ε-diaminopimelic acid, glutamic acid, and alanine [436]. NUCLEOTIDES apparently containing D-alanine and D-gltumamic acid have been isolated from Staphylococcus aureus Cells [356] exposed to penicillin. The formation of adenylosuccinic acid—a nucleotide containing aspartic acid—has been established in Yeast cells [437] (p. 312). There is also other Evidence for the presence of substances in natural sources that represent compounds of amino acids with CARBOHYDRATES [341, 438].

During the autocatalytic Activation of Trypsinogen, a peptide is cleaved from it [439, 440], which has the following Structure:

Cleavage of a peptide is also observed during The conversion of fibrinogen into fibrin in the presence of Thrombin [441]. Another example of peptide cleavage from a protein molecule is provided by the conversion of egg albumin into plakalbumin [442, 443] under the action of subtilisin (a proteinase from B. subtilis).

A number of acylated amino acids occur in nature. Pantothenic acid serves as a typical example:

Pantothenic acid is a widely distributed B-complex vitamin; it occurs mainly in the form of coenzyme A. Other Examples of naturally occurring acylamino acids include: acetylaspartic acid, benzoylglycine (hippuric acid), a,δ-dibenzoylornithine (ornithuric acid), phenylacetylglycine (phenaceturic acid), phenylacetylglutamine, a- and δ-acetylornithine, fumaryl-DL-alanine [444], biocytin [445], and glycocholic acid.

¹ See note on p. 69.