Summary Allergens and antigens of Bermuda grass pollen fractionated by SDS‐polyacrylamide gel electrophoresis and transferred to nitrocellulose membranes were identified using twenty‐one sera of Bermuda grass pollen‐allergic patients. The IgE‐ and IgG‐binding pollen components transferred to nitrocellulose were detected by reaction with enzyme‐labelled anti‐human IgE and anti‐human IgG, respectively. There was heterogeneity in both IgE‐ and IgG‐binding patterns of the allergic sera tested. Fourteen pollen components, ranging in molecular weight from 16000 to 88000 daltons, bound to IgE antibodies. Only two of the fourteen allergens identified reacted with IgE antibodies of more than 50% of the twenty‐one allergic sera. The pollen component with a molecular weight of 32000 daltons showed by far the highest frequency of IgE binding, being recognized by sixteen (76%) of the twenty‐one sera examined. Fifteen (71 %) of the twenty‐one sera tested had IgE antibodies that reacted with more than one of the fourteen allergenic components identified. Pollen components recognized by IgE antibodies also reacted with IgG antibodies, and there were components only recognized by IgG antibodies. Results obtained from this study should be useful both clinically and in research.

Murine liver-derived inhibitory protein (LIP) capable of inhibiting human lymphocyte proliferation was highly purified from liver extract. Its molecular weight determined by gel filtration and SDS-PAGE was 105,000 and 38,400 respectively. LIP moved electrophoretically at the gamma-globulin region. Its activity in inhibiting lymphocyte proliferation was temperature-stable up to 60 degrees C, and pH-stable between 4 and 11. It was not cytotoxic to lymphocytes as shown in 51Cr-release experiments. The purified LIP possessed arginase activity.