1. The Role of Arginine-Phenylalanine-Amide-Related Peptides in Mammalian Reproduction
Mohammad Saied Salehi, Amin Tamadon, Mohammad Reza Jafarzadeh Shirazi, Mohammad Reza Namavar, Mohammad Javad Zamiri Int J Fertil Steril. 2015 Oct-Dec;9(3):268-76. doi: 10.22074/ijfs.2015.4540. Epub 2015 Oct 31.
Until 2000 it was believed that gonadotropin-releasing hormone (GnRH) was the sole regulator of hypophyseal gonadotropes. In 2000, the discovery of a gonadotropin inhibitory hormone (GnIH) initiated a revolution in the field of reproductive physiology. Identification of GnIH homologues in mammals, the arginine-phenylalanine-amide (RFamide)-related peptides (RFRPs), indicated a similar function. Subsequently, further works conducted in various laboratories worldwide have shown that these neuropeptides inhibit the hypothalamic-hypophyseal axis. This review discusses the role of RFRPs in mammalian reproductive processes.
2. Structures of D-amino-acid amidase complexed with L-phenylalanine and with L-phenylalanine amide: insight into the D-stereospecificity of D-amino-acid amidase from Ochrobactrum anthropi SV3
Seiji Okazaki, Atsuo Suzuki, Tsunehiro Mizushima, Hidenobu Komeda, Yasuhisa Asano, Takashi Yamane Acta Crystallogr D Biol Crystallogr. 2008 Mar;64(Pt 3):331-4. doi: 10.1107/S0907444907067479. Epub 2008 Feb 20.
The crystal structures of D-amino-acid amidase (DAA) from Ochrobactrum anthropi SV3 in complex with L-phenylalanine and with L-phenylalanine amide were determined at 2.3 and 2.2 A resolution, respectively. Comparison of the L-phenylalanine amide complex with the D-phenylalanine complex reveals that the D-stereospecificity of DAA might be achieved as a consequence of three structural factors: (i) the hydrophobic cavity in the region in which the hydrophobic side chain of the substrate is held, (ii) the spatial arrangement of Gln310 O and Glu114 O epsilon2 that fixes the amino N atom of the substrate and (iii) the existence of two cavities that keep the carboxyl/amide group of the substrate near or apart from Ser60 O gamma.
3. Effect of alpha-resorcylic acid-L-phenylalanine amide on collagen synthesis and matrix metalloproteinase expression in fibroblasts
Seon-Yeong Kwak, Jin-Mi Noh, Suyeon Lee, So Hun Lee, Su-ji Jeon, Hye-In Kim, Jong-Ho Kim, Yoon-Sik Lee Bioorg Med Chem Lett. 2014 Feb 1;24(3):742-5. doi: 10.1016/j.bmcl.2013.12.110. Epub 2014 Jan 3.
Regulation of collagen synthesis and matrix metalloproteinases (MMPs) expression levels has been an important issue in medicinal, pharmaceutical and cosmetic industries. Herein, α-Resorcylic acid-phenylalanine amide (α-RA-F) was prepared and its biological activities were observed. We found that α-RA-F boosted collagen synthesis and reduced MMPs expression levels in human fibroblasts without cytotoxicity.
