No abstract

After pronase digestion of bovine fibrinogen, the asparagine-linked glycans were released from the resulting glycopeptides by hydrazinolysis, and subsequently re-N-acetylated. Two sialylated glycans wcrc isolated by ionexchange chromatography. Their primary structure has been determined by mcthylation analysis and 360-MHz 'H-NMR spectroscopy. The structures proposed to be present in the native glycoprotein are as follows:Fibrinogen and fibrin from a number of animal species are glycoproteins [I]. The biological role of their glycan moieties is not yet clear despite active investigations in this field. For example, it has been reported that neutral carbohydrates [2] or sialic acid [3] are released during clotting but a number of investigations were unable to confirm these results [4, 51. The decrease in coagulability of fibrinogen after periodate oxidation of glycans also suggested a role of the latter in the clotting process [6]. This finding has since been critized, as the reduction of the clotting time may be due to oxidation of some amino acid residues [7]. Recently, it was demonstrated that the enzymatic removal of glycans does not change the clotting time of fibrinogen [8].Study of pathological cases did not bring more information about the relationship between sugars and clotting. In fact congenitally abnormal fibrinogens [9 -1 I] have in some ciiscs a lower carbohydrate content than normal ones but is seems that the primary cause of these coagulation disturbances is an amino acid substitution. However, sialic-acidfree fibrinogen forms a gel different from the normal protein [I21 and yields urea-soluble fibrin in thc presence of factor XI11 [13]. Thesc findings suggest that the carbohydrate in fibrinogen could play a role in the complex polymerisation process.Attempts to clarify the structure of the glycan of bovine fibrinogen were done earlier by Mester et al. [ 14, IS], but due to the poor performances of the analytical methods used at that time, the authors did not obtain exact determination of the structure. The present paper describes the primary structure of the two major glycans of bovine fibrinogen deter-('orre.s/7:llonc(c./~~f~ to

Rat leukocyte elastase has been purified successively by AH-Sepharose Kappa-elastin affinity chromatography and by ion exchange chromatography on a carboxymethyl Sephadex resin. It has great similarities with human leukocyte elastase in its molecular weight, substrate specificity and inhibitory profile. The effect of rat leukocyte elastase inhibitors in influencing the chemotactic response of rat PMN to fMetLeuPhe has been compared to that of other proteinase inhibitors. The results indicated that oleoyl (Ala)2ProValCH2Cl, a specific inhibitor of human and rat leukocyte elastases and Eglin C, which also inhibits human and rat cathepsin G, are among the powerful inhibitors of rat PMN chemotaxis induced by the formyl oligopeptide. This suggests that these neutral proteinases, in addition to their known participation in connective tissue catabolism, could play a role in PMN locomotion and chemotaxis.