13861-02-4Relevant academic research and scientific papers
Reevaluating the Substrate Specificity of the L-Type Amino Acid Transporter (LAT1)
Chien, Huan-Chieh,Colas, Claire,Finke, Karissa,Springer, Seth,Stoner, Laura,Zur, Arik A.,Venteicher, Brooklynn,Campbell, Jerome,Hall, Colton,Flint, Andrew,Augustyn, Evan,Hernandez, Christopher,Heeren, Nathan,Hansen, Logan,Anthony, Abby,Bauer, Justine,Fotiadis, Dimitrios,Schlessinger, Avner,Giacomini, Kathleen M.,Thomas, Allen A.
, p. 7358 - 7373 (2018/08/06)
The L-type amino acid transporter 1 (LAT1, SLC7A5) transports essential amino acids across the blood-brain barrier (BBB) and into cancer cells. To utilize LAT1 for drug delivery, potent amino acid promoieties are desired, as prodrugs must compete with millimolar concentrations of endogenous amino acids. To better understand ligand-transporter interactions that could improve potency, we developed structural LAT1 models to guide the design of substituted analogues of phenylalanine and histidine. Furthermore, we evaluated the structure-activity relationship (SAR) for both enantiomers of naturally occurring LAT1 substrates. Analogues were tested in cis-inhibition and trans-stimulation cell assays to determine potency and uptake rate. Surprisingly, LAT1 can transport amino acid-like substrates with wide-ranging polarities including those containing ionizable substituents. Additionally, the rate of LAT1 transport was generally nonstereoselective even though enantiomers likely exhibit different binding modes. Our findings have broad implications to the development of new treatments for brain disorders and cancer.
Biotransformation of new racemic (R,S)-5-benzylhydantoin derivatives by D-hydantoinases from adzuki bean
Latacz, Gniewomir,Kie?-Kononowicz, Katarzyna
, p. 117 - 124 (2014/04/17)
In the present work the scope of D-hydantoinase enzyme application was increased towards new racemic (R,S)-5-benzylhydantoin derivatives. Five new substrates for the D-hydantoinase (R,S)-5-(3′-carboxybenzyl)hydantoin, (R,S)-5-(4′-carboxybenzyl)hydantoin, (R,S)-5-(2′-carbomethoxybenzyl) hydantoin, (R,S)-5-(3′-carbomethoxybenzyl)hydantoin and (R,S)-5-(4′(4-ethoxycarboxy)propoxybenzyl)hydantoin were synthesised and converted using a two-step hydantoinase process into their corresponding D-phenylalanine derivatives. In this study two D-hydantoinases from Vigna angularis (adzuki bean) obtained from commercial sources were used: pure, isolated directly from Vigna angularis (V.a.D-HYD) 494 U/g and immobilised, recombinant, cloned and expressed in Escherichia coli (rD-HYD) 53.1 U/g. The results obtained showed that the examined enzymes catalysed hydrolysis of all new substrates into their corresponding N-carbamoyl-D-phenylalanine derivatives. High enantiomeric purities of the resulting D-phenylalanine derivatives were also determined. However, very low conversion yields of (R,S)-5-(3′- carboxybenzyl)hydantoin and (R,S)-5-(2′-carbomethoxybenzyl)hydantoin to corresponding N-carbamoyl-D amino acid were observed. Three D-phenylalanine derivatives: 4-carboxy-D-phenylalanine, 3-carbomethoxy-D-phenylalanine and 4-carbopropoxy-D-phenylalanine were obtained and isolated from the reaction mixtures using ion-exchange chromatography.
Design, synthesis and brain uptake of lat1-targeted amino acid prodrugs of dopamine
Peura, Lauri,Malmioja, Kalle,Huttunen, Kristiina,Lepp?nen, Jukka,H?m?l?inen, Miia,Forsberg, Markus M.,Rautio, Jarkko,Laine, Krista
, p. 2523 - 2537 (2013/09/24)
Purpose: Drug delivery to the brain is impeded by the blood-brain barrier (BBB). Here, we attempted to enhance the brain uptake of cationic dopamine by utilizing the large amino acid transporter 1 (LAT1) at the BBB by prodrug approach. Methods: Three amino acid prodrugs of dopamine were synthesized and their prodrug properties were examined in vitro. Their LAT1-binding and BBB-permeation were studied using the in situ rat brain perfusion technique. The brain uptake after intravenous administration and the dopamine-releasing ability in the rat striatum after intraperitoneal administration were also determined for the most promising prodrug. Results: All prodrugs underwent adequate cleavage in rat tissue homogenates. The prodrug with phenylalanine derivative as the promoiety had both higher affinity for LAT1 and better brain uptake properties than those with an alkyl amino acid -mimicking promoiety. The phenylalanine prodrug was taken up into the brain after intravenous injection but after intraperitoneal injection the prodrug did not elevate striatal dopamine concentrations above those achieved by corresponding L-dopa treatment. Conclusions: These results indicate that attachment of phenylalanine to a cationic drug via an amide bond from the meta-position of its aromatic ring could be highly applicable in prodrug design for LAT1-mediated CNS-delivery of not only anionic but also cationic polar drugs.
