Immunochemical Studies on Arachis hypogaea Proteins With Particular Reference to the Reserve Proteins. I. Characterization, Distribution, and Properties of α-Arachin and α-Conarachin

Abstract

Abstract. Fourteen antigenic constituents have been detected in A rachis hypogaea seeds. The major proteins of the classic arachin and conarachin fractions have been identified. Arachin contains 4 antigens (the major one called a-arachin) and conarachin contains 2 which have been called a,, and a2-conarachin. Structural differences between a-arachin, a1 and a2-conarachin are indioated by their different antigenic specificities. a-Arachin precipitates as a separate entity at low temperature. The action of trypsin on this protein induces an increase in electrophoretic mobility and prevents precipitation at low temperature. This enzyme has no detectable effect on a., and a,-conarachin.The proteins of the ootyledon and of the entire axis are quite similar in their immunoelectrophoretic patterns. However, quantitative and qualitative differences oocur between the proteins found in the cotyledon and those of the 1-millimeter tip of the axis. In the latter, there is a 4-fold smaller proportion of a-arachin than in the cotyledon. Immunoelectrophoretic analysis of subcellular preparations from cotytedons confirms that a-arachin is an aleurin and that c1-conarachin is a typical cytoplasmic protein. Large and small aleurone grains appear very similar in their qualitative antigenic composition.Proteins extracted from mature seeds of Arachis hypogaea appear heterogeneous by chromatography on DEAE-cellulose, ultracentrifugation and polvacrylamide gel electrophoresis (7, 10). Moreover, 2 of the reserve proteins, a-arachin and a-conarachin, associate or dissociate under different conditions of pH and ionic strength (17,18,19) to make the precise identification of individual components difficult or even uncertain. The fact that these 2 proteins exhibit similar electrophoretic mobilities (16) suggests structural similarities.Because of their high degree of specificity, immunological methods offer another approach for the study of peanut proteins. A general picture of the total proteins was established and the 2 major reserve proteins were characterized after submission to phys-

Embryonal antigens in maize caryopses: The temporal order of antigen accumulation during embryogenesis

“…Much less data are available concerning selective gene expression and its timing in higher plants. Changes in antigen spectra seem to accompany the growth and differentiation of plant cells in vitro (Boutenko and Volodarsky, 1968) and in vivo (Wright, 1963 ;Daussant et al, 1969 ;Millerd et al, 1971;Misharin et al, 1974). However, most Abbreviations : DAP = day(s) after pollination; EA = embryonal antigen (s) of these changes appear to be of a quantitative nature (Kawashima etal., 1967;Ivanov etal., 1974) and therefore do not unambiguously prove the synthesis of new proteins.…”

Physicochemical Studies on the Proteins of the Peanut Cotyledon and Embryonic Axis

“…The immunoelectrophoretic patterns of the total axial (even numbers) and the total cotyledonary (odd numbers) proteins are shown in Figure 3. The identification of these designated components is based on the report by Daussant et al (5). In those studies, both a-arachin and a-conarachin were purified on DEAE-cellulose to give homogenous species according to sedimentation analysis and chromatography on DEAE-cellulose.…”

“…The major proteins of classic arachin and conarachin have been named a-arachin and a-conarachin. Although homogenous by zone electrophoresis and sedimentation analysis, immunoelectrophoresis has shown that arachin contains four proteins (a-arachin being the major component) and a-conarachin contains two components called al-and a2-conarachin (5,6). …”

“…The globulins, considered primarily as the reserve or storage proteins of the seed, were first classified by Johns and Jones (10) and by Jones and Horn (14) according to their solubility in ammonium sulfate. The two classic globulin fractions, arachin and conarachin, have been studied extensively by several investigators (4,5,(11)(12)(13). They exist as complex systems with sedimentation and electrophoretic patterns which change considerably, depending upon the experimental conditions employed.…”

“…Estimation of antigen concentrations by immunodiffusion was performed according to Ouchterlony (18). Immunoelectrophoresis was carried out according to Grabar and Williams (9) and to Daussant et al, (5 RESULTS DEAE-cellulose Chromatography. DEAE-cellulose chromatograms of the total cotyledonary (A) and total axial (B) proteins show similar qualitative patterns ( Fig.…”