生物化学技术

Transcription factors recruit a wide variety of associated co-factors to regulate gene expression. These co-factors include protein kinases, phosphatases, deacetylases, methylases, and ubiquitin ligases, etc. To identify novel protein kinases associated with transcrip ...

RNA polymerase II (Pol II) plays a crucial role in eukaryotic biology since it is necessary for the expression of all protein-coding genes as well as most microRNAs and several small nuclear RNAs. Pol II is specifically recruited to core promoter DNA via its association with general transcripti ...

Differential gene expression is facilitated by transcriptional regulatory mechanisms and chromatin modifications through DNA–protein interactions. One of the widely used assays to study this is chromatin immunoprecipitation (ChIP) assay, which enables analysis of asso ...

Eukaryotic gene regulation is controlled, in part, by inducible transcription factor-binding regulatory sequences in a tissue-specific and hormone-responsive manner. The development of methods for the analysis of transcription factor interaction within native chromat ...

Transcription factor NFκB comprises a family of proteins that serve as crucial regulators of genes involved in host immune and inflammatory responses, cell survival, proliferation, and differentiation. Since transcription of NFκB-dependent genes is increased in numerous inf ...

Using a synthetic oligopeptide (d-Phe)4, a microorganism Bacillus cereus DF4-B producing alkaline d-peptidase (ADP) was isolated. The enzymatic properties have been characterized; the enzyme showed d-stereospecific dipeptidyl aminopeptidase and endopeptidase activ ...

d-Amino acid oxidase and d-aspartate oxidase are two well-known FAD-containing flavooxidases that catalyze the same reaction (the oxidative deamination) on different d-amino acids. d-aspartate oxidase is specific for acidic d-amino acids (i.e., d-aspartate and d-glutamate) and d- ...

d-Amino acids play important physiological roles in the mammalian body. Recent investigations revealed that, in mammals, d-amino acids are synthesized from their corresponding l-enantiomers via amino acid racemase. This article describes a method used to measure amino acid racem ...

Serine racemase is a glial and neuronal enzyme that reversibly converts l-serine to d-serine, an endogenous co-agonist of N-methyl-d-aspartate receptor type glutamate receptors (NMDARs). Here we present methods to recombinantly express and purify serine racemase in bacteria and t ...

This paper describes a method for determining the nutritional value of d-amino acids, d-peptides, and amino acid derivatives using a growth assay in mice fed a synthetic all-amino acid diet. A large number of experiments were carried out in which a molar equivalent of the test compound replaced a nut ...

Recent studies have shown that biologically uncommon d-β-aspartic acid residues accumulate in specific proteins during the aging process. However, aspartyl residues are not racemized uniformly because d-Asp appears to be confined to particular sites in these proteins. We here desc ...

The presence of d-amino acids in foods is promoted by harsh technological processes (e.g., high temperature or extreme pH values) or can be the consequence of adulteration or microbial contamination (d-amino acids are major components of the bacterial cell wall). For this reason, quality con ...

The NMDA subtypes of glutamatergic receptors (NMDARs) are unusual in that their activation requires the binding of both glutamate and a co-agonist glycine or d-serine. Whereas glycine was first suggested to play such a role, it was later established that d-serine could serve as an endogenous co ...

d-Serine is a transmitter-like molecule that physiologically activates NMDA receptors in the brain. Although d-serine was thought to be exclusively released by astrocytes, we recently demonstrated endogenous d-serine release from neurons in cultures and slices. So far high-perf ...

d-Amino acids play several key roles and are widely diffused in living organisms, from bacteria (in which d-alanine is a component of the cell wall) to mammals (where d-serine is involved in glutamatergic neurotransmission in the central nervous system). The study of the biological processes ...

Estimation of chronological age is essential in forensic and archeological science. The racemization method is one of the best methods to meet the demands of these scientific fields, providing both accuracy of the estimated age and simplicity of technique. In general, living organs are com ...

d-Amino acids are stereoisomers or optical isomers of naturally occurring l-amino acids and thus possess the same chemical structure, but may differ in their biological/physiological properties. Until a half century ago, d-amino acids had been considered to be unnatural substances f ...

Chemoselective reactions are important tools for the modification of peptides and proteins. Thereby the modification is desired to be site specific and bioorthogonal. Here we describe the site-specific modification of azido-proteins via a Staudinger-type phosphite ligation. ...

Unnatural amino acid mutagenesis allows us to introduce unnatural α-amino acids into internal positions of proteins in response to expanded codons such as amber and four-base codons. To improve the unnatural amino acid mutagenesis, the incorporation of unnatural α-amino acids and non- ...

Expanding the repertoire of genetically encoded amino acids in cultured mammalian cells requires the expression of the bacterial or archaeal pair of a tRNA and an aminoacyl-tRNA synthetase variant engineered to be specific to the amino acid, along with the supplementation of an unnatural ...