Linderstrplm-Lang and Ottesen have reported the discovery of a bacterial enzyme which brings about the transformation of ovalbumin to a new, easily crystallizable protein, plakalbumin. Unlike other proteolytic processes, this reaction seems to involve the rupture of a limited number of peptide bonds, with the release of only slightly over 1 per cent of the total ovalbumin nitrogen (1, 2). Ville...

By determining the extent of racemization of aspartic acid in a well-dated bone, it is possible to calculate the in situ first-order rate constant for the interconversion of the L and D enantiomers of aspartic acid. Collagen-based radiocarbon-dated bones are shown to be suitable samples for use in "calibrating" the racemization reaction. Once the aspartic-acid racemization reaction has been "ca...

The strain of Escherichia coli K-12 with high aspartase activity was irradiated with UV. After mutagenesis and selection, the mutant B-715 was isolated which was 4-times more active in L-aspartic acid biosynthesis than parental K-12 strain. The highest productivity was achieved while the strain was cultivated in the ammonium fumarate medium in 37 degrees C for 18-30 hours. It was found that bet...

The microbial and enzymatic hydrolysis of poly(aspartic acid) (PAA) has been reviewed. Two PAA-degrading bacteria (Pedobacter sp. KP-2 and Sphingomonas sp. KT-1) were isolated from flesh river water. Pedobacter sp. KP-2 hydrolyzed PAA of high molecular weights over 5000. Sphingomonas sp. KT-1 hydrolyzed only PAA of low molecular weights (<5000), while the cell extract could hydrolyze high-molec...

A new peptide antibiotic complex B-43, active against Gram-positive and Gram-negative bacteria, was isolated from a strain of Bacillus circulans. This antibiotic contains aspartic acid, valine, isoleucine, leucine, phenylalanine and 2,4-diaminobutyric acid. It seems to be related to polypeptin and antibiotic complex 4205, but differs in that it contains aspartic acid residue.

Toxin production in a large number of Pyrenophora teres isolates have been investigated. During fungal growth, the pH of the medium decreases from 6.5 to about 3.0. Aspergillomarasmine A is the major toxin excreted into the culture medium. Nonenzymatic acid-catalyzed conversion of aspergillomarasmine A to anhydroaspergillomarasmine A proceeds at low pH and is prevented by repeated titration of ...

A preceding paper described the characteristics of the isolated enzyme system, prepared from ox liver acetone powder, which catalyzes the conversion of citrulline and aspartic acid to arginine and malic acid. It was shown that the fundamental requirements for arginine synthesis from citrulline are aspartic acid, Mg++, and adenosine triphosphate (ATP), the latter as a reactant in substrate conce...

Wzx belongs to a family of membrane proteins involved in the translocation of isoprenoid lipid-linked glycans, which is loosely related to members of the major facilitator superfamily. Despite Wzx homologs performing a conserved function, it has been difficult to pinpoint specific motifs of functional significance in their amino acid sequences. Here, we elucidate the topology of the Escherichia...