Versatile building blocks in the form of novel derivatives of 1,6‐anhydro‐β‐lactose have been used for the rapid and highly efficient synthesis of various proteoglycan core structures (see example). The resulting oligosaccharide–tetrapeptide conjugates can be used to investigate the mechanism of biosynthesis of glycosaminoglycans in human cartilage cells. Bn=benzyl.

Genome analysis has indicated that plants, like animals, possess a variety of protease genes. However, bulk of putative proteases has not been characterized at the enzyme level. In this article, a novel enzyme that hydrolyses phenylalanyl-4-methylcoumaryl 7-amide (phenylalanyl-MCA) was purified from cotyledons of daikon radish by ammonium sulphate fractionation and successive chromatography with DEAE-cellulose, phenyl-Sepharose, Sephacryl S-200 and Mini-Q. The molecular mass of the enzyme was estimated to be 78 kDa by SDS-PAGE under reducing conditions and 74 kDa by gel filtration, indicating that the enzyme is a monomer. The deduced amino acid sequence from the cDNA nucleotide sequence indicated that the enzyme is an orthologue of Arabidopsis unidentified protein, acylpeptide hydrolase-like protein (AHLP; UniProt ID: Q9FG66) belonging to the prolyl oligopeptidase (POP) family of a serine-type peptidase predicted from genetic information. Good substrates identified for the enzyme include phenylalanyl-MCA, tyrosyl-MCA and enkephalin. Neither acylamino acid-releasing activity nor endopeptidase activity was detected. The enzyme cleaved enkephalin (YGGFM, YGGFL), whereas, BAM-12 P (YGGFMRRVGRPE) and dynorphin A (YGGFLRRIRPKLK) were not digested. These results suggested that the enzyme possesses strict size selectivity of substrate. We propose the name 'tyrosyl aminopeptidase' for the uncharacterized protein AHLP.

Vielseitig verwendbare Derivate der 1,6‐Anhydro‐β‐lactose wurden als Bausteine für die schnelle und hoch effiziente Synthese von Proteoglycan‐Kernstrukturen genutzt (siehe Schema). Die gebildeten Oligosaccharid‐Tetrapeptid‐Konjugate können eingesetzt werden, um den Mechanismus der Glycosaminoglycan‐Biosynthese in menschlichen Knorpelzellen zu untersuchen. Bn=Benzyl.