Unique peptide:N-glycanase of Caenorhabditis elegans has activity of protein disulphide reductase as well as of deglycosylation.
Peptide:N-glycanase (PNGase) is the enzyme responsible for de-N-glycosylation of misfolded glycoproteins in the cytosol. Here, we report the molecular identification and characterization of PNGase (png-1, F56G4.5) from Caenorhabditis elegans. This enzyme released both high mannose- and complex-type N-glycans from glycopeptides and denatured glycoproteins. Deglycosylation activity was inhibited by Zn(2+) and z-VAD-fmk, but not by EDTA. PNG-1 has a thioredoxin-like domain in addition to a transglutaminase domain, the core domain of PNGases, and exhibited protein disulphide reductase activity in vitro. Our biochemical studies revealed that PNG-1 is a unique bifunctional protein possessing two enzyme activities.
Kato
Toshihiko
T
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Kawahara
Akihito
A
Ashida
Hisashi
H
Yamamoto
Kenji
K
D000595:Amino Acid Sequence; D000818:Animals; D017173:Caenorhabditis elegans / Q000201:enzymology*; D006031:Glycosylation; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase / Q000737:chemistry* / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012260:Ribonucleases / Q000378:metabolism; D013879:Thioredoxins / Q000737:chemistry / Q000378:metabolism
D011994:Recombinant Proteins; D013879:Thioredoxins; D009247:NADH, NADPH Oxidoreductases; D012260:Ribonucleases; C029600:ribonuclease B; D043524:Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase