The biosynthesis of platelet-activating factor (PAF), a phospholipid autocoid with potent ulcerogenic properties that is produced in secretory exocrine glands by physiological secretagogues, was assessed in microsomal preparations of glandular gastric mucosa. For this purpose, 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67); the enzymes of the ...

Addition of 1-O-alk-1'-enyl-2-lyso-sn-glycero-3-phosphoethanolamine (alkenyl-lyso-GPE) to human neutrophil membrane preparations containing 1-O-[3H]hexadecyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (1-O-[3H]alkyl-2-arachidonoyl-GPC) resulted in rapid deacylation of the 1-O-[3H]alkyl-2-arachidonoyl-GPC to 1-O-[3H]alkyl-2-lyso-GPC (lyso-platelet-activating factor, lyso-PAF). When acetyl-CoA...

As a follow-up to our effort establish reliable thermodynamic data for amino acids, the heat capacity and phase behavior are reported N-acetyl glycine amide (CAS RN: 2620-63-5), N-acetyl-L-alanine 15962-47-7), N-acetyl-L-valine 37933-88-3), N-acetyl-L-isoleucine 56711-06-9), N-acetyl-L-leucine 28529-34-2). Prior measurement, thermogravimetric analysis X-ray powder diffraction were performed det...

Mass-balanced (1)H/(2)H-isotope dipeptide tag (MBIT) is diversified as aliphatic tags for multiplexed protein quantification. Aliphatic MBITs are based on the N-acetyl-Xxx-Ala dipeptide, where Xxx is an artificial amino acid with a linear alkyl side chain from C(2)H(5) to C(8)H(17) (C(2)-C(8) tags). (1)H/(2)H isotopes are encoded in the methyl groups of N-acetyl and Ala to yield a pair of isoba...

The influence of alkyl 3-position substituents on the rate of amide isomerization N-terminal to proline and hydroxyproline has been explored via the synthesis and analysis of (2S)-N-(acetyl)proline N′-methylamide (1), (2S,4R)and (2S,4S)-N-acetyl-4-hydroxyproline N′-methylamides 2 and 3, and their respective 3,3-dimethyl analogues 4-6. The relative populations of the amide cis and trans isomers ...

Platelet-activating factor (PAF, 1-0-alkyl-2-acetylsn-glycero-3-phosphocholine) is a biologically active phospholipid synthesized by a variety of cell types upon appropriate stimulation. PAF is a potent hypotensive factor and it activates platelets and inflammatory cells at concentrations as low as 10”’ M. Removal of the acetyl moiety at the sn-2 position abolishes the biological activity and t...