A series of C-terminus capped dipeptides and tripeptides was synthesized as growth hormone (GH) secretagogues. Among them, tripeptide Aib-D-Trp-D-homoPhe-OEt showed low nanomolar activity in the rat pituitary assay. Thus, we have demonstrated that the GH secretagogue activity of the hexa- hepta-GH releasing peptides can be mimicked at the tripeptide level. (C) 1998 Elsevier Science Ltd. All rights reserved.
Preparation of cross-linked enzyme aggregates of l-aminoacylase via co-aggregation with polyethyleneimine
摘要:
L-Aminoacylase from Aspergillus melleus was co-aggregated with polyethyleneimine and subsequently cross-linked with glutaraldehyde to obtain aminoacylase-polyethyleneimine cross-linked enzyme aggregates (termed as AP-CLEA). Under the optimum conditions, AP-CLEA expressed 74.9% activity recovery and 81.2% aggregation yield. The said method of co-aggregation and cross-linking significantly improved the catalytic stability of L-aminoacylase with respect to temperature and storage. AP-CLEA were employed for enantioselective synthesis of three unnatural amino acids (namely: phenylglycine, homophenylalanine and 2-naphthylalanine) via chiral resolution of their ester-. amide- and N-acetyl derivatives. The enantioselectivity of AP-CLEA was the highest for hydrolysis of amino acid amides; was moderate for hydrolysis of N-acetyl amino acids and was the least for hydrolysis of amino acid esters. Furthermore, AP-CLEA were found to retain more than 92% of the initial activity after five consecutive batches of (RS)-homophenylalanine hydrolysis suggesting an adequate operational stability of the biocatalyst. (C) 2011 Elsevier B.V. All rights reserved.
Preparation of cross-linked enzyme aggregates of l-aminoacylase via co-aggregation with polyethyleneimine
作者:Bhalchandra K. Vaidya、Suyog S. Kuwar、Sandeep B. Golegaonkar、Sanjay N. Nene
DOI:10.1016/j.molcatb.2011.10.003
日期:2012.2
L-Aminoacylase from Aspergillus melleus was co-aggregated with polyethyleneimine and subsequently cross-linked with glutaraldehyde to obtain aminoacylase-polyethyleneimine cross-linked enzyme aggregates (termed as AP-CLEA). Under the optimum conditions, AP-CLEA expressed 74.9% activity recovery and 81.2% aggregation yield. The said method of co-aggregation and cross-linking significantly improved the catalytic stability of L-aminoacylase with respect to temperature and storage. AP-CLEA were employed for enantioselective synthesis of three unnatural amino acids (namely: phenylglycine, homophenylalanine and 2-naphthylalanine) via chiral resolution of their ester-. amide- and N-acetyl derivatives. The enantioselectivity of AP-CLEA was the highest for hydrolysis of amino acid amides; was moderate for hydrolysis of N-acetyl amino acids and was the least for hydrolysis of amino acid esters. Furthermore, AP-CLEA were found to retain more than 92% of the initial activity after five consecutive batches of (RS)-homophenylalanine hydrolysis suggesting an adequate operational stability of the biocatalyst. (C) 2011 Elsevier B.V. All rights reserved.
Tripeptide growth hormone secretagogues
作者:Lihu Yang、Greg Morriello、Yanping Pan、Ravi P. Nargund、Khaled Barakat、Kristine Prendergast、Kang Cheng、Wanda W.-S. Chan、Roy G. Smith、Arthur A. Patchett
DOI:10.1016/s0960-894x(98)00103-6
日期:1998.4
A series of C-terminus capped dipeptides and tripeptides was synthesized as growth hormone (GH) secretagogues. Among them, tripeptide Aib-D-Trp-D-homoPhe-OEt showed low nanomolar activity in the rat pituitary assay. Thus, we have demonstrated that the GH secretagogue activity of the hexa- hepta-GH releasing peptides can be mimicked at the tripeptide level. (C) 1998 Elsevier Science Ltd. All rights reserved.