scholarly journals Binding of α2-macroglobulin and limulin: regulation of the plasma haemolytic system of the American horseshoe crab, Limulus

2000 ◽  
Vol 347 (3) ◽  
pp. 679-685 ◽  
Author(s):  
Snehasikta SWARNAKAR ◽  
Rengasamy ASOKAN ◽  
James P. QUIGLEY ◽  
Peter B. ARMSTRONG
Keyword(s):  
Horseshoe Crab ◽  
Solid Phase ◽  
Haemolytic Activity ◽  
Thiol Ester ◽  
The Third ◽  
Α2 Macroglobulin ◽  
Sialic Acid Binding ◽  
Small Primary ◽  
Solid Phase Assay ◽  
Binding Lectin

The mediator of haemolysis in the plasma of the horseshoe crab, Limulus polyphemus, is limulin, a sialic acid-binding lectin. The haemolytic activity of limulin is inhibited by thiol ester-reacted forms of Limulus α2-macroglobulin, the third-most abundant protein of the plasma. Limulus α2-macroglobulin that has experienced cleavage of its internal thiol ester bond, consequent to reaction with proteases, or with the small primary amine, methylamine, reduces the haemolytic activity of limulin when present at molar excesses that approximate the relative concentrations of these two proteins in the plasma. Native, unreacted Limulus α2-macroglobulin has no effect on the haemolytic activity of limulin. Limulin binds thiol ester-reacted forms of Limulus α2-macroglobulin both in a solid-phase assay and in solution with an avidity 10-25 times higher than native, unreacted Limulus α2-macroglobulin. Protease-reacted α2-macroglobulin functions as a marker for the presence of foreign proteases in the blood of Limulus, and thus of pathogenic organisms that release proteases as facilitators of invasion and pathogenicity. Modulation of the haemolytic system represents a novel function for α2-macroglobulin.

scholarly journals A new haemagglutinin from the amoebocytes of the horseshoe crab Carcinoscorpius rotundicauda. Purification and role in cellular aggregation

1985 ◽  
Vol 230 (2) ◽  
pp. 321-327 ◽  
Author(s):  
S Srimal ◽  
D T Dorai ◽  
M Somasundaran ◽  
B K Bachhawat ◽  
T Miyata
Keyword(s):  
Horseshoe Crab ◽  
Cell Aggregation ◽  
Blood Group A ◽  
Sialic Acid Binding ◽  
Cellular Aggregation ◽  
Group A ◽  
And Function ◽  
Single Subunit ◽  
Binding Lectin ◽  
Cell Cell

The present paper describes the purification and function of a haemagglutinin from the amoebocyte lysate of the horseshoe crab Carcinoscorpius rotundicauda. The purified protein consisted of a single subunit of Mr 24 000 and agglutinated human blood-group-A+ erythrocytes. Its haemagglutinin activity was inhibited by purified lysate, coagulogen, but not by sugars. The haemagglutinin differed immunologically and in activity from the sialic-acid-binding lectin carcinoscorpin present in the haemolymph. It caused aggregation of forma-fixed amoebocytes, and on the basis of this observation its role in cell-cell adhesion is proposed. This new haemagglutinin promotes cell-cell aggregation in amoebocytes in a manner that shares some similarities with thrombospondin-mediated platelet aggregation in vertebrates [Jaffe, Leuang, Nachman, Levin & Moseher (1981) Nature (London) 295, 246-248].

scholarly journals Limulus α2-macroglobulin. First evidence in an invertebrate for a protein containing an internal thiol ester bond

1987 ◽  
Vol 248 (3) ◽  
pp. 703-707 ◽  
Author(s):  
P B Armstrong ◽  
J P Quigley
Keyword(s):  
Proteinase Inhibitor ◽  
Thermal Denaturation ◽  
Horseshoe Crab ◽  
Proteinase Inhibitors ◽  
Binding Activity ◽  
Ester Bond ◽  
Thiol Groups ◽  
Thiol Ester ◽  
Complement Proteins ◽  
Α2 Macroglobulin

Intra-chain thiol ester bonds are present in a limited number of proteins. The thiol ester class of proteins includes vertebrate alpha 2-macroglobulin and the complement proteins C3 and C4. We report here the first instance of a thiol ester protein from an invertebrate, the alpha 2-macroglobulin proteinase-inhibitor homologue present in the plasma of the American horseshoe crab Limulus polyphemus. Our evidence is of three kinds: (1) the proteinase-binding activity of Limulus alpha 2-macroglobulin is inactivated by the low-molecular-mass primary amine methylamine; (2) the native protein is subject to autolytic fragmentation during mild thermal denaturation, yielding fragments of approx. 125 kDa and 55 kDa, whereas the methylamine-treated protein is stable under these conditions of thermal treatment; (3) new thiol groups are generated rapidly during reaction of the protein with trypsin. The demonstration of the thiol ester bond in a protein from an ancient invertebrate provides evolutionary evidence for the importance of this bond in the function of plasma forms of the alpha 2-macroglobulin-like proteinase inhibitors.

scholarly journals On the multispecificity of carcinoscorpin, the sialic acid binding lectin from the horseshoe crab Carcinoscorpius rotundacauda

FEBS Letters ◽  
1982 ◽  
Vol 148 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Devarajan Thambi Dorai ◽  
Mohan Somasundaran ◽  
Subita Srimal ◽  
Bimal Kumar Bachhawat
Keyword(s):  
Sialic Acid ◽  
Horseshoe Crab ◽  
Sialic Acid Binding ◽  
Binding Lectin

Further characterization of the sialic acid-binding lectin from the horseshoe crab Carcinoscorpius rotunda cauda

1981 ◽  
Vol 209 (1) ◽  
pp. 325-333 ◽  
Author(s):  
D.Thambi Dorai ◽  
B.K. Bachhawat ◽  
S. Bishayee ◽  
K. Kannan ◽  
D.Rajagopal Rao
Keyword(s):  
Sialic Acid ◽  
Horseshoe Crab ◽  
Sialic Acid Binding ◽  
Binding Lectin

scholarly journals Correction: α2-Macroglobulin-like protein 1 can conjugate and inhibit proteases through their hydroxyl groups, because of an enhanced reactivity of its thiol ester

2021 ◽  
Vol 296 ◽  
pp. 100208
Author(s):  
Seandean Lykke Harwood ◽  
Nadia Sukusu Nielsen ◽  
Kathrine Tejlgård Jensen ◽  
Peter Kresten Nielsen ◽  
Ida B. Thøgersen ◽  
...  
Keyword(s):  
Hydroxyl Groups ◽  
Thiol Ester ◽  
Α2 Macroglobulin

scholarly journals Porcine Arterivirus Infection of Alveolar Macrophages Is Mediated by Sialic Acid on the Virus

2004 ◽  
Vol 78 (15) ◽  
pp. 8094-8101 ◽  
Author(s):  
Peter L. Delputte ◽  
Hans J. Nauwynck
Keyword(s):  
Sialic Acid ◽  
Alveolar Macrophages ◽  
Sialic Acids ◽  
Respiratory Syndrome Virus ◽  
Specific Monoclonal Antibody ◽  
Neuraminidase Treatment ◽  
Acid Binding Protein ◽  
Sialic Acid Binding ◽  
High Mannose ◽  
Binding Lectin

ABSTRACT Recently, we showed that porcine sialoadhesin (pSn) mediates internalization of the arterivirus porcine reproductive and respiratory syndrome virus (PRRSV) in alveolar macrophages (Vanderheijden et al., J. Virol. 77:8207-8215, 2003). In rodents and humans, sialoadhesin, or Siglec-1, has been described as a macrophage-restricted molecule and to specifically bind sialic acid moieties. In the current study, we investigated whether pSn is a sialic acid binding protein and, whether so, whether this property is important for its function as a PRRSV receptor. Using untreated and neuraminidase-treated sheep erythrocytes, we showed that pSn binds sialic acid. Furthermore, pSn-specific monoclonal antibody 41D3, which blocks PRRSV infection, inhibited this interaction. PRRSV attachment to and infection of porcine alveolar macrophages (PAM) were both shown to be dependent on the presence of sialic acid on the virus: neuraminidase treatment of virus but not of PAM blocked infection and reduced attachment. Enzymatic removal of all N-linked glycans on the virus with N-glycosidase F reduced PRRSV infection, while exclusive removal of nonsialylated N-linked glycans of the high-mannose type with endoglycosidase H had no significant effect. Free sialyllactose and sialic acid containing (neo)glycoproteins reduced infection, while lactose and (neo)glycoproteins devoid of sialic acids had no significant effect. Studies with linkage-specific neuraminidases and lectins indicated that α2-3- and α2-6-linked sialic acids on the virion are important for PRRSV infection of PAM. From these results, we conclude that pSn is a sialic acid binding lectin and that interactions between sialic acid on the PRRS virion and pSn are essential for PRRSV infection of PAM.

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