A recombinant D92G mutant sialidase from Micromonospora viridifaciens has been cloned, expressed and purified. Kinetic studies reveal that the replacement of the conserved aspartic acid with glycine results in a catalytically competent retaining sialidase that possesses significant activity against activated substrates. The contribution of this aspartate residue to the free energy of hydrolysis...

The aim of this research was the comparative study content amino acids in herb and tubers Stachys sieboldii. acid composition raw materials carried out using high-performance liquid chromatography (HPLC). results obtained have shown that aerial parts plants investigated higher than underground organs. Free bound L-aspartic acid, L-proline, L-phenylalanine were present analyzed samples greatest ...

Urinary amino acid chromatograms were studied from 33 patients with various types of leukaemia and 71 control subjects. Marked variations were found in the excretion of methionine, threonine, valine, leucine, tyrosine, histidine, and aspartic acid.

We have previously proposed that tRNA(Gly) was the first tRNA and glycine was the first amino acid incorporated into the genetic code. The next two amino acids incorporated would have been the other two small hydrophilic amino acids serine and aspartic acid, which occurred through the duplication of the tRNA(Gly) sequence, followed by mutation of its anticodon by single C to U transition mutati...

α-Amylases are glycoside hydrolase enzymes that act on the α(1→4) glycosidic linkages in glycogen, starch, and related α-glucans, and are ubiquitously present in Nature. Most α-amylases have been classified in glycoside hydrolase family 13 with a typical (β/α)8-barrel containing two aspartic acid and one glutamic acid residue that play an essential role in catalysis. An atypical α-amylase (BmaN...

Details in the fermentation of oxytetracycline in a synthetic medium with Streptomyces rimosus have been presented. In these studies, an organic nitrogen source was shown to be essential for the production of significant amounts of antibiotic activity. Of the amino acids tested, aspartic acid, proline, threonine, valine, and beta-alanine were utilized well for both growth and antibiotic product...

The single molecular conductance of amino acids was measured by a scanning tunneling microscope (STM) break junction. Conductance measurement of alanine gives out two conductance values at 10-1.85 G₀ (1095 nS) and 10-3.7 G₀ (15.5 nS), while similar conductance values are also observed for aspartic acid and glutamic acid, which have one more carboxylic acid group compared with alanine. This may ...

We have analyzed a panel of T cell hybridomas specific for the chemically dominant epitope of hen egg-white lysozyme 48-61 which has asparagine 59 as an important T cell receptor contact residue. A number of T cells recognize 48-61 with asparagine at position 59, but not the aspartic acid or isoaspartic acid derivatives. Conversely, we find T cells that specifically recognize 48-61 bearing an i...

A crude enzyme preparation from a nadA mutant of Escherichia coli was used to catalyze the conversion of [14C]aspartic acid into a precursor of quinolinic acid, a key intermediate in the biosynthesis of nicotinamide adenine dinucleotide.

therefore, that the medium exerts no effect on•g traing•h . Sort and quantity of nitrogen sources None of those 10 strains could grow in the rmedium containing Lglutamlc acid, L-aspartic acid and L-methionlne (2). Upon examining the nitrogen requirement of about 60 wild Flexner type dysentery bacilli , even the most exacting strains of which were found to grow in the medium containing L-glutami...