The N‐and O‐linked carbohydrate chains of human, bovine and porcine plasminogen

Abstract

The structures of the N‐and O‐glycans of human, bovine and porcine plasminogen were determined by 500‐MHz 1H‐NMR spectroscopy. The N‐glycans of all three species proved to be of the N‐acetyllactosamine type differing from one another with respect to the sialylation and fucosylation patterns. In the N‐glycan of human plasminogen the two antennae are sialylated with N‐acetylneuraminic acid (NeuAc), whereas in the bovine counterpart both branches carry significant amounts of N‐glycolylneuraminic acid (NeuGc). In porcine plasminogen the sialic acid is mainly NeuAc; the Manα1→6 branch, however, is only partially sialylated. In addition, the porcine N‐glycan is fucosylated to about 80% in α1→6 linkage to the GlcNAc‐1 residue. The O‐glycans of the three species possess an identical Galβ1→3GalNAc core which is α2→3 sialylated with NeuAc at Gal. The disialylated form, which is also present in all three species, has an additional NeuAc residue in α2→6 linkage to GalNAc. Mono‐and disialylated forms occur in different molar ratios in the different plasminogens: 80:20 in human, 70:30 in bovine and 50:50 in porcine. This study on the carbohydrate moiety of these three plasminogens reveals species specificity in terms of various types of microheterogeneities.

Microfluidic Chip-LC/MS-based Glycomic Analysis Revealed Distinct N-glycan Profile of Rat Serum

“…2b ). Among the four mixed N- glycans, i.e ., Hex 5 HexNAc 4 NeuAc 1 NeuGc 1 , Hex 5 HexNAc 4 NeuAc 1 NeuGc 1 + OAc, Hex 5 HexNAc 4 dHex 1 NeuAc 1 NeuGc 1 , and Hex 5 HexNAc 4 dHex 1 NeuAc 1 NeuGc 1 + OAc, only Hex 5 HexNAc 4 NeuAc 1 NeuGc 1 was found on bovine plasminogen and porcine vitronectin 40 41 and mice serum 42 . This is the first time that this type of sialylated N- glycan has been identified in rats.…”

A study on the regulation of N‐glycoloylneuraminic acid biosynthesis and utilization in rat and mouse liver

“…However, there are instances where NeuSGc is heterogeneously distributed among the glycan chains of certain glycoconjugates. The sialic acids of 0-linked glycan chains on bovine plasminogen, for example, contain about 94% NeuSAc, whereas the sialic acids on the N-linked chains of the same molecule consist of only 29% Neu5Ac [35]. Similarly, in certain fractions of porcine submandibular mucin, NeuSAc occurs preferentially in a(2 + 3) linkages to Gal while NeuSGc shows a tendency to be bound by x ( 2 -+ 6 ) linkages to GalNAc [36].…”

Effects of Glycosylation on the Enzymatic Activity and Mechanisms of Proteases

“…In 1988, a groundbreaking NMR study on the glycosylation of porcine, bovine and human plasmin, revealed the positions and composition of the O - and N -glycans [165]. The now well defined form 1 of human plasmin, in which the N -glycan at Asn288 with terminal sialic acids was altered to a high mannose glycan (GlcNAc 2 Man 9 ), exhibited a k cat / K M of about 6%, due to interference with substrate binding in the kringle 3 domain (Figure 3F) [139,166].…”

“…Novel methods or old techniques with new applications may facilitate the analysis of glycans on natural proteins, in particular NMR [165,184]. Thus, we are looking forward to a new era of combined efforts from different structural biological methods, which can elucidate the architecture and behavior of naturally glycosylated proteins.…”