Characterization of in vitro expressed human alpha-fetoprotein as highly reproducible reference material for clinical immunoassays.
Explore the source record for details and available documents.
Amino Acid Sequence↗
Biomedical subjects
B Terrana
Publications and source records attributed to B Terrana.
Sialyglycoconjugates release during in vitro capacitation of human spermatozoa.
Modifications of the human sperm surface during incubation in capacitating conditions were studied by radiolabeling terminal sialic acid residues of cell surface glycoconjugates using the sodium metaperiodate/sodium tritiated borohydride method. During in vitro capacitation, sialyglycoconjugates were released from the human sperm surface according to well reproducible kinetics. This release could be inhibited by the presence of seminal plasma in the capacitation buffer. Two principal size classes of sialyglycoconjugates were detected in the capacitation medium and analyzed by gel filtration chromatography and SDS-PAGE. The smaller class was characterized by glycopeptides less than 5,000 Da, whereas the larger class was characterized by two sialyglycoproteins of approximately 15,000-16,000 and 22,000-23,000 Mr. The role of human albumin, a key component of the capacitation buffer, in the removal of these molecules from the sperm surface was studied in light of its constant association with large amounts of released material.
Adult↗
Monoclonal antibodies recognizing a recombinant portion of human alpha-fetoprotein with antigenic selectivity versus albumin.
Determination of serum alpha-fetoprotein is useful in the clinical management of liver cancer, but it has not been particularly helpful in the early diagnosis of this disease, since also non-neoplastic liver diseases may result in small increases of its serum concentration. To improve the clinical performance of this assay, we have previously developed an in vitro culture system, in which the expression of alpha-fetoprotein and albumin could be coordinately modulated by thyroid hormone. This system allowed large scale production and purification of native alpha-fetoprotein to be used as reference material. In addition, we synthesized and cloned in a bacterial expression vector a DNA sequence coding of human alpha-fetoprotein amino acid sequence 38-119. This alpha-fetoprotein sequence was chosen since it is the least homologous to albumin, being the amino acid sequence of the two proteins extremely similar with an overall identity of about 38%. Now we have obtained three hybridomas recognizing with high affinity and specificity both the recombinant fragment and native alpha-fetoprotein. These antibodies, which therefore recognize the native protein in the amino acid sequence 38-119, should allow the development of an immunoassay for alpha-fetoprotein with absolute selectivity versus albumin. This might result in more sensitive clinical determinations, avoiding the possibility of cross-reactions.
Albumins↗