Affiliations: [a] Institute for Biomedical Engineering, and Department of AMES-Bioengineering, University of California, San Diego, La Jolla, CA 92093-0681, USA | [b] Departments of Human Genetics and Development, Microbiology, and Physiology and Cellular Biophysics, College of Physicians and Surgeons, Columbia University, NY, NY 10032, USA
Correspondence:
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Address correspondence to: Dr. Lanping Amy Sung, Department of AMES-Bioengineering, mail code 0861, University of California at San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0861, Tel.: (619) 534-5250, Fax: (619) 534-3658
Abstract: The adhesive energy in lectin-induced agglutination can be assessed by the deformation of erythrocytes in aggregates. Helix pomatia (HPA) and Dolichos biflorus (DBA) specifically agglutinated blood group A erythrocytes and induced a change in curvatures of cells at the end of the aggregates. The curvatures changed from concavity to convexity with increasing lectin concentrations. HPA-induced aggregates achieved the theoretical maximal end cell curvature of 0.27 μm−1 at 2–3 μg/ml; DBA-induced aggregates approached 0.23 μm−1, requiring 400 μg/ml. At any given lectin concentration, HPA showed greater surface binding, caused higher cell curvatures, induced larger aggregate size, and had greater adhesive energies, as compared to DBA. HPA and DBA are globular proteins with a diameter of ∼5.5 nm and ∼6.1 nm, respectively, as revealed by the negative staining electron microscopy. The former induced uniform intercellular spacing (∼15 nm), whereas the latter induced both smooth (∼20 nm) and ruffled spacings. The uniform intercellular spacing was not a function of lectin concentrations. Microscopic studies of erythrocyte deformation provided morphological correlates of biophysical findings of differential adhesive energies induced by these two blood group A-specific lectins.
Keywords: Lectin, agglutination, deformation, erythrocytes, blood-group, electron microscopy
DOI: 10.3233/BIR-1994-31405
Journal: Biorheology, vol. 31, no. 4, pp. 353-364, 1994
