Guinea pig immunoglobulins

In the 12 complete sequences shown in Fig. 4.14, 25 positions are invariant. Many of these residues are also correspondingly located and invariant in the Vh regions of mouse, rabbit, and guinea pig immunoglobulins. In the human proteins these include the 2 half-cystines, Trp 38 and 49,5 of 7 amino acids in positions 92-98, and positions 120, 122, and 123, which are at the junction of the V and C regions. (IgM becomes clearly distinguishable from IgG at position 124 and thereafter.) This relatively invariant sequence at the V/C junction is also con-... 

Ig of Rabbit, Mouse, Guinea Pig, and Horse VI. GUINEA PIG IMMUNOGLOBULINS... 

Zlokovic, B.V., et al. 1990. A saturable mechanism for transport of immunoglobulin G across the blood-brain barrier of the guinea pig. Exp Neurol 107 263. 

Furthermore, SpA is not highly specific for IgG, as first thought, since fractions of human IgM, IgA, and IgE have been found to interact with SpA. This property of SpA is not restricted to human immunoglobulins, but is true for the most species tested except rabbits, guinea pigs and horses. 

DOBSON, C., MORSETH, D.J. SOULSBY, J.L. (1971) Immunoglobulin E-type antibodies induced by Ascaris suum infections in guinea pigs. Journal of Immunology, 106, 128-133. 

Sheep erythrocytes sensitized with intact immunoglobulin G or with reduced (dithioerythritol) and alkylated (iodoacetamide) antibody have been lysed by guinea-pig serum, indicating that reduced and alkylated antibody bound and activated complement. Observations suggested that the sole effect of reduction of antibody disulphide bonds was to diminish the co-operativity of antibody-complement interaction. 

The protection afforded the fetus by the mother occurs by transfer of immunoglobulins from the maternal circulation to the fetal circulation across the placental barrier (the chorioallantoic placenta). This is not true of all species of mammals. In some the yolk sac appears to be the major route across which immunoglobulins are transferred (e.g., rabbit, guinea pig, and mouse). In others, such as goats, cows, and sheep, no immunoglobulins are transferred during intrauterine life but are obtained by the neonate from maternal colostrum by absorption across the gut. In some mammals (mouse, rat, dog) both pre- and postnatal transfer occurs (Schlamowitz, 1976). 

A study of the three-dimensional structure of the pF fragment of guinea pig IgGl, a non-covalent dimer of the 0 3 homology sub-unit, is reported.From quantitative H n.m.r. studies on the and pF fragments of rabbit immunoglobulin G it is concluded that there is a two-fold axis of symmetry in these fragments that leads to reduced tine widths. ... 

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