ABSTRACT
The concept of "internal image" of antiidiotypic antibodies has provided the basis for eliciting catalytic antibodies. A monoclonal IgM 9A8 that was obtained as an antiidiotype to AE-2 mAb, a known inhibitor of acetylcholinesterase, displayed esterolytic activity. Study of recombinant Fab fragments and separate light and heavy chains of 9A8 confirmed that the antibody variable domain encodes the catalytic function, whereas neither part of the primary sequence of the Fab exhibited homology with the enzyme. The specific modification of the 9A8 variable domain by an active site-directed covalent inhibitor revealed the presence of an active site Ser residue. A three-dimensional modeling suggests the existence of a functional catalytic dyad Ser-His. Comparison of active sites of 9A8 and 17E8 esterolytic abzyme raised against transition-state analog revealed structural similarity although both antibodies were elicited by two different approaches.
Subject(s)
Antibodies, Monoclonal/chemistry , Molecular Mimicry , Amino Acid Sequence , Animals , Antibodies, Catalytic/metabolism , Antibodies, Monoclonal/genetics , Antibodies, Monoclonal/metabolism , Base Sequence , Binding Sites , Cloning, Molecular , DNA Primers , Humans , Mice , Models, Chemical , Molecular Sequence DataABSTRACT
Peptide T has a sequence (Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr) belonging to HIV envelope that is involved in the interaction with CD(4) receptor of T lymphocytes. Research of protease activities towards this peptide is very relevant for AIDS therapy. Characterization of specificity of subtilisin Carlsberg towards this very hydrophilic peptide is proposed by using high-performance liquid chromatography and mass spectrometry. Peptide T was totally hydrolysed by the protease after 24 h. Separation of hydrophilic fragments was perfected with an hydrophilic stationary phase and a reversed acetonitrile gradient. Peptide masses were determined by ion spray mass spectrometry. Four primary and one secondary hydrolysis products were found, corresponding to cleavage at the carboxylic side of threonine. Specifities of subtilisin Carlsberg towards the Segments 19 to 26 of bovine pancreatic ribonuclease A, an homologous fragment of peptide T, and peptide T were compared.
ABSTRACT
A case of linear pigmentation of three fingernails is reported. Following extraction of the nail of the thumb the matrix displayed a 2X4 mm circumscribed pigmented area. Histologic examination revealed a junction nevus.
Subject(s)
Nails/pathology , Pigmentation Disorders/pathology , Adult , Diagnosis, Differential , Female , Humans , Nevus, Pigmented/diagnosis , Nevus, Pigmented/therapy , Pigmentation Disorders/etiology , Pigmentation Disorders/therapy , Precancerous ConditionsABSTRACT
Six cases of syphilides- rarely seen cutaneous manifestations today--are reported and the difficulties in finding the correct diagnosis are stressed. Considerations with particular reference to the differential diagnosis of clinically and histomorphologically similar diseases are discussed. Beside case history and serological tests it is of overall importance to bear in mind the possibility of late syphilis.
Subject(s)
Syphilis, Cutaneous/diagnosis , Aged , Bowen's Disease/diagnosis , Diagnosis, Differential , Female , Humans , Lupus Vulgaris/diagnosis , Male , Middle Aged , Sarcoidosis/diagnosis , Syphilis SerodiagnosisABSTRACT
Reduced transport fluid (RTF) was modified by altering its pH and by the addition of a yeast dialysate. This reduced transport yeast-containing fluid (RTYF) was shown to be superior to RTF in maintaining viability of Neisseria gonorrhoeae in cultures and in clinical material.
