407-64-7

Aldehyde dehydrogenase 9A1 (ALDH9A1) is a human enzyme that catalyzes the NAD+-dependent oxidation of the carnitine precursor 4-trimethylaminobutyraldehyde to 4-N-trimethylaminobutyrate. Here we show that the broad-spectrum ALDH inhibitor diethylaminobenzaldehyde (DEAB) reversibly inhibits ALDH9A1 in a time-dependent manner. Possible mechanisms of inhibition include covalent reversible inactivation involving the thiohemiacetal intermediate and slow, tight-binding inhibition. Two crystal structures of ALDH9A1 are reported, including the first of the enzyme complexed with NAD+. One of the structures reveals the active conformation of the enzyme, in which the Rossmann dinucleotide-binding domain is fully ordered and the inter-domain linker adopts the canonical β-hairpin observed in other ALDH structures. The oligomeric structure of ALDH9A1 was investigated using analytical ultracentrifugation, small-angle X-ray scattering, and negative stain electron microscopy. These data show that ALDH9A1 forms the classic ALDH superfamily dimer-of-dimers tetramer in solution. Our results suggest that the presence of an aldehyde substrate and NAD+ promotes isomerization of the enzyme into the active conformation.

The invention relates to betaine and especially relates to a method of preparing butyl betaine, which can avoid generation of butyrolactone, increase product purity and reduce cost, wherein 4-dimethylamino butyric acid, methanol, alkali and an ionic liquid are used as raw materials and are reacted with monochloromethane and diluted hydrochloric acid to obtain the butyl betaine. The raw materials are commercial products and have broad raw materials in abundant supply, so that raw material cost is low and production cost is effectively controlled. During the reaction, generation of impurities, such as butyrolactone, is prevented, so that the produced butyl betaine is high in quality.

Betaines belong to the naturally occurring osmoprotectants or compatible solutes present in a variety of plants, animals and microorganisms. In recent years, metabolomic techniques have been emerging as a fundamental tool for biologists because the constellation of these molecules and their relative proportions provide with information about the actual biochemical condition of a biological system. Therefore, identification and characterization of biologically important betaines are crucial, especially for metabolomic studies. Most of the natural betaines are derived from amino acids and related homologues. Although, theoretically, all the amino acids can be converted to corresponding betaines by simple methylation of the amine group, only a few of the amino acid-derived betaines were fully characterized in the literature. Here, we report a combined electrospray ionization tandem and high-resolution mass spectrometry study of all the betaines derived from amino acids, including the isomeric betaines. The decomposition pathway of protonated, sodiated and potassiated molecule ions that enable unambiguous characterization of the betaines including the isomeric betaines and overlapping ionic species of different betaines is distinctive. Copyright

The molecular design of useful cosolutes for polymerase chain reaction (PCR), which is one of the most important techniques in molecular biology, plays a significant role in amplification of highly stable genome sequences because during PCR, strand dissociation sometimes fails due to high melting temperature. Here, we designed and synthesized eight new zwitterionic cosolutes derived from glycine betaine, a destabilizing reagent for GC-rich DNA duplexes, and systematically compared their ability to destabilize DNA duplexes and to amplify genome DNA by PCR. We found that introduction of n-butyl groups rather than methyl groups into the ammonium group reduced the melting temperature of DNA duplexes 11-fold more than what was observed for the scaffold cosolute, glycine betaine, and furthermore, the cosolute can amplify the stable genome sequence by PCR.

The invention relates to preparation of high purity 3-carboxy-N,N,N-trimethyl-1-propanaminium hydroxide inner salt by saponification of 3-trimethylaminiumbutanoic acid ester salt and following precipitation of inorganic salts with carbon dioxide or sulfur dioxide.

The conformation of flexible zwitterionic molecules in solutions of polar solvents is studied by means of a NMR chemical shift method.This method makes use of chemical shift changes of NMR lines, induced by the electrostatic field caused by the electrical charges of the zwitterion.The electrostatic field at the observed nucleus is calculated, taking distances of zwitterionic (trimethylammonio)alkanoates in aqueous and methanolic solutions are then deduced from the 13C NMR chemical shift data as a function of the number of methylenes linking the cationic and anionic groups of the zwitterion.The comparison of experimental data with the end to end distances predicted by the rotational isomerism state theory shows that the polymethylene chain has a more folded conformation than the free chain.Electrostatic attraction between the two zwitterionic charges is thus important, although it could be expected that it could be offset by steric hindrance, i.e., by the bulkiness of terminal charged groups.

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