Comparative immunochemical and immunocytochemical study of 3 soluble granulocytic proteins in blood cells and serum

Using immunofluorescence, it has been shown that leukocyte thermostable alpha-glycoprotein (LTAG) and leukocyte beta-globulin (LBG) are, like lactoferrin, components of polynuclear leukocytes. These proteins were found in the perinuclear zone, cytoplasm membrane and extracellularly. Serum LTAG concentration increases in immune inflammatory diseases. In severe forms of diabetes and glomerulonephritis there is a rise in LBG concentration. The biological role of LTAG and LBG is unknown.     

Comparative immunochemical study of the serum proteins of Lacertilia (Reptilia)]

The immunochemical relationships of the serum proteins of Uromastix acanthinurus, Agama mutabilis, Oplurus cuvieri, O. quadrimaculatus, Chamaeleo chamaeleon, Chalcides ocellatus and Lacerta lepida were studied by means of immunoelectrophoresis with an antiserum anti-Uromastix successively absorbed. Homogeneity of the Iguania species was pointed out and they were found more closely related to the Scincid Chalcides ocellatus than to the Lacertid Lacerta lepida. Within the Iguania, the two Agamids are immunologically more closely related to the Chamaeleon than to the two Iguanids.     

Structural studies on membrane-bound and soluble growth-hormone-binding proteins of rabbit liver.

Covalent cross-linking techniques have been used to investigate the structural characteristics of the growth-hormone (GH) receptor in a variety of rabbit liver cell membrane preparations (particulate and soluble). Two classes of GH-binding protein have been identified which differ in their Mr by gel filtration and susceptibility to precipitation with poly(ethylene glycol) (PEG). The first, a PEG-precipitable (Mr approximately 300,000) protein, contained Mr-65,000 and Mr-40,000 binding proteins linked by disulphide bonds. It was present in aqueous extracts derived from microsomal membranes but was not present in cytosol preparations. The second, a PEG-non-precipitable protein (Mr approximately 100,000) was composed of a non-disulphide-linked primary GH-binding subunit of Mr 60,000-66,000. This binding protein was present in all rabbit liver cell fractions and/or preparations. Both binding-protein classes contained intramolecular disulphide bonds. It is not clear whether the Mr-approximately 100,000 form, or perhaps higher-Mr species which have not been identified by cross-linking studies, represents the native, endogenous, form of the GH receptor present in particulate microsomal or plasma membranes. Accordingly, although these data have identified two classes of GH-binding protein, especially a primary GH-binding subunit of Mr 60,000-66,000, they indicate that, unlike studies on the insulin receptor, covalent cross-linking techniques alone are not sufficient to delineate the complete subunit structure of the native and endogenous form of the GH receptor.     

An electrophoretic and immunochemical characterization of human surfactant-associated proteins

We have prepared an antiserum against a serum-free extract of alveolar proteinosis lavage that recognizes the same proteins as an antiserum to human surfactant. Using one and two-dimensional gel electrophoresis, protein blotting and immunostaining we have found proteins with Mr of approx. 35 and 60 kDa to be present in every source of human surfactant we have examined. These proteins are immunologically related to those found in the lavage from alveolar proteinosis patients, have the same electrophoretic characteristics and are not found in serum. The 35 kDa protein is a group of at least eight isoforms ranging in relative molecular mass Mr from 32 to 36 kDa with isoelectric points between 4.8 and 5.5. Neuraminidase digestion studies have shown that at least part of this charge heterogeneity may be due to sialic acid residues. The less abundant form, with a Mr of about 60 kDa is also a sialoglycoprotein with similar isoelectric points.     

Isolation and immunochemical characteristics of soluble membrane proteins from the cell wall of Corynebacterium diphtheria

A method for isolation of immunochemically active proteins from Corynebacterium diphtheria membranes was elaborated. The proteins were solubilized with the nonionic detergent NP-40 and gel-filtered through an Ultrogel AcA-34 column under denaturating conditions. The purified proteins (Mr = 64 kD) were antigenically active in a solid phase radioimmunoassay with human antidiphtheria antibodies.