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C Mihaesco

Publications and source records attributed to C Mihaesco.

At least 37 records · Page 2Linked to original sources
PubMed1971

Interchain and intrachain disulfide bridges of a human immunoglobulin M: detection of a unique fragment.

Studies of the amino acid sequences around half-cystine residues in an immunoglobulin M have revealed an unexpectedly high number. At least 14 different sequences were found in the mu chain (V(HIII) subclass). Four of these were involved in interchain disulfide bridges and at least 10 in intrachain bridges. Five came from the kappa chain (kappa(III) subclass, Inv b). Several others, although having a high degree of homology, were not identical with those of either the mu or kappa chains. These results support the concept of an additional fragment in gammaM molecules, although its function and localization remain to be determined.

Amino Acid Sequence↗
PubMed1969

Immunochemical studies in four cases of alpha chain disease.

Studies of a number of properties of the pathological gammaA-proteins in the first four cases of the recently recognized alpha-chain disease demonstrate that, as in gamma-heavy-chain disease, the abnormal protein is devoid of light chains and represents a portion of the alpha-heavy chain related to the Fc-fragment. In two patients, serum electrophoresis showed a broad abnormal band, whereas in the two others the pathological protein was not noticeable on the electrophoretic pattern. The diagnosis of alpha-chain disease can be established without purification of the protein by immuno-electrophoresis and gel diffusion experiments using selected antisera to gammaA and a reference alpha-chain disease protein. All four proteins belonged to the alpha1-subclass, displayed electrophoretic heterogeneity, and showed a strong tendency to polymerize. The polymers occurred in vivo and were held together both by disulfide bonds and by strong noncovalent forces. Two of the three purified proteins had a very high carbohydrate content. The abnormal protein was always found in concentrated urines in variable but generally low amounts. It was not detected in parotid saliva but was present in significant amounts in jejunal fluid of all four patients. The alpha-chain disease protein was shown to be associated with the secretory piece in external secretions of two patients. The clinicopathological features were strikingly similar in the four patients. All patients were affected with a neoplastic and mostly plasmacytic proliferation involving primarily the whole length of the small intestine and the mesenteric nodes and all exhibited a severe malabsorption syndrome. While Israeli authors have emphasized the frequency of this type of abdominal lymphoma in young Arabs and non-Ashkenazi Jews, two of our patients were Kabyles, one a Syrian Arab, and one an Eurasian. Cellular studies showed that the pathological protein was synthesized by the proliferating cells in the lymphoid tissue of the digestive tract and in the mesenteric nodes, and that there was no detectable light-chain synthesis at the intracellular level.

Blood Protein Disorders↗
PubMed1968

Papain digestion fragments of human IgM globulins.

Papain digestion of two Waldenström IgM globulins produced a high amount of small peptides and resulted in the formation of two end products, the Fabmicro and Fcmicro fragments. The Fcmicro fragment is characterized by a fast electrophoretic mobility, a high content in carbohydrate, and a high molecular weight. It was demonstrated that this fragment is made of heavy chain pieces belonging to several disulfide-linked monomeric subunits, presumably representing the carboxy-terminal end of the micro-chains. Fc fragments from the two macroglobulins could not be distinguished immunologically. An appreciable proportion of IgM molecules apparently underwent degradation without the formation of a stable Fc fragment. An Fc-like fragment, analogous to the reduced Fc fragment, was obtained at early stages of papain digestion of the IgM subunits. The Fabmicro fragment, with slow and individually distinct electrophoretic mobility, bears many physicochemical and immunological similarities to the Fabgamma fragment. It consists of one light chain and one Fd piece, both of which were isolated. The interaction of these two constituents was demonstrated by gel diffusion studies. Fab fragments of both IgM globulins were resolved into two subpopulations with different electric charges. In addition to these fragments, intermediary split products were observed at early stages of the degradation process, together with a high yield of small peptides mainly derived from the papain-sensitive region of the heavy chains. Immunologic data strongly suggested that this segment of micro-chains is situated between the Fd piece and the portion included in the Fc fragment. Several experiments indicated the importance of conformational antigenic specificity in both Fab and Fc regions of the IgM globulins.

Carbohydrates↗
PubMed1966

Antigenic determinants common to human immunoglobulins G and M: importance of conformational antigens.

Antiserums produced against certain isolated human myeloma IgGglobulins and absorbed in order to show only individual antigenic specificity crossreact with certain Waldenstrom IgM-globulins. Some of the common antigenic determinants revealed by these cross-reactions depend on the tertiary and quaternary structure of the IgG and IgM molecules and are independent of their K and L light-chain antigenic types.

Antigen-Antibody Reactions↗