A NEW SPECIES ( FLAVOBACTERIUM POLYGLUTAMICUM ) WHICH HYDROLYZES THE γ- l -GLUTAMYL BOND IN POLYPEPTIDES

Abstract

It has been shown (Kovacs and Bruckner, 1952; Bruckner et al., 1953a, 1953b, 1953c) that certain bacteria produce glutamyl polypeptides in which the y-glutamyl bond predominates; that produced by Bacillus anthracis (Ivainovics and Erd6s, 1937; Ivanovics and Bruckner, 1937; Hanby and Rydon, 1946) and by Bacillus mesentericus (Bruckner and Ivdnovics, 1937) contains the D-isomer alone, whereas that formed by Bacillus subtilis (Bovarnick, 1942) contains both D-and L-isomers in varying quantities (Thorne et al., 1954). Confirmatory evidence for the presence of the 'y-glutamyl bond has been provided recently by work with synthetic 'y-poly-L-(Waley, 1955; Bruckner et al., 1955a) and-y-poly-D-glutamic acid (Bruckner et al., 1955b). Other natural products in which y-glutamyl residues occur include pteroylglutamic acid conjugates and p-aminobenzoylpolyglutamic acid. These substances are important growth factors and are split by conjugases (Stokstad, 1954). It was thought that an organism that can grow on the bacterial polypeptide and can specifically split the 'y-glutamyl linkages might serve as the source of an enzyme to demonstrate the existence of 'y-glutamyl bonds in proteins.2 Indeed, it has been reported (Haurowitz and Bursa, 1949) that 'y-linked glutamic acid occurs in proteins, but this has not been conclusively demonstrated since there is as yet no reliable method for distinguishing between a-and-y-bonds in protein; an improved chemical method was recently described by Haurowitz and Horowitz (1956).

Poly‐gamma‐glutamate in bacteria

“…and Myrothecium sp. γ‐glutamylhydrolases cleave PGA between two l ‐glutamates (Volcani and Margalith, 1957; Tanaka et al ., 1993; 1997). Finally, the B. subtilis γ‐glutamylhydrolase encoded by pgsS , previously known as ywtD or pgdS , cleaves PGA between two d ‐glutamates (Ashiuchi et al ., 2003).…”

Microbial Degradation of Poly(amino acid)s

“…The last enzymatic activity that should be mentioned was the first γ-PGA degrading exoenzyme that was characterized; Volcani and Margalith identified an intracellular enzyme activity in the soluble fraction of crude extract prepared from Flavobacterium polyglutamicum cells . The extract hydrolyzed γ- d / l -PGA only in the γ- l -glutamic acid rich regions but completely degraded γ- l -PGA to free l -glutamic acid, which was identified by paper chromatography and manometric determination employing the glutamic acid decarboxylase reaction.…”

“…The extract hydrolyzed γ- d / l -PGA only in the γ- l -glutamic acid rich regions but completely degraded γ- l -PGA to free l -glutamic acid, which was identified by paper chromatography and manometric determination employing the glutamic acid decarboxylase reaction. The remaining γ- d -PGA containing oligomers of the polymer chain were not identified …”

“…The remaining γ-D-PGA containing oligomers of the polymer chain were not identified. 80 Recently, a γ-PGA hydrolase (PghP) was purified and characterized from bacteriophage ΦNIT1 infected B. subtilis cells that degraded PGA via γ-glutamic acid oligomers to tri-, tetra-, and penta-γ-glutamate. 81 This hydrolase showed sensitivity to the metalloprotease inhibitor EDTA and required Zn 2+ or Mn 2+ to restore catalytic activity.…”

Carboxypeptidase displaying differential velocity in hydrolysis of methotrexate, 5-methyltetrahydrofolic acid, and leucovorin

“…on September 1, 2020 by guest http://jb.asm.org/ Downloaded from 512 ALBRECHT, BOLDIZSAR, AND HUTCHISON Hydrolysis of teropterin (pteroyl--y,-y-triglutamate) to diopterin (pteroyldiglutamate) and partial cleavage of -y-L-glutamyl-L-glutamic acid possibly reflect the presence of a contaminating enzyme (29) or, in fact, limited activity of the carboxypeptidase per se with -y-L-glutamyl-Lglutamic acid. Similarly, the presence of a peptidase specific for the aspartyl moiety (20) or non-specificity of the Flavobacterium sp.…”