Biomedical subjects

S M Zurawski

Publications and source records attributed to S M Zurawski.

24 records · Page 2Linked to original sources

PubMed1988

Identification of three critical regions within mouse interleukin 2 by fine structural deletion analysis.

We have analyzed structure--function relationships of the protein hormone murine interleukin 2 by fine structural deletion mapping. A total of 130 deletion mutant proteins, together with some substitution and insertion mutant proteins, was expressed in Escherichia coli and analyzed for their ability to sustain the proliferation of a cloned murine T cell line. This analysis has permitted a functional map of the protein to be drawn and classifies five segments of the protein, which together contain 48% of the sequence, as unessential to the biological activity of the protein. A further 26% of the protein is classified as important, but not crucial, for the activity. Three regions, consisting of amino acids 32-35, 66-77 and 119-141 contain the remaining 26% of the protein and are critical to the biological activity of the protein. The functional map is discussed in the context of the possible role of the identified critical regions in the structure of the hormone and its binding to the interleukin 2 receptor complex.

Amino Acid Sequence↗

PubMed1987

Species-specificity of T cell stimulating activities of IL 2 and BSF-1 (IL 4): comparison of normal and recombinant, mouse and human IL 2 and BSF-1 (IL 4).

Mouse and human interleukin 2 (IL 2) both cause proliferation of T cells of the homologous species at high efficiency. Human IL 2 also stimulates proliferation of mouse T cells at similar concentrations, whereas mouse IL 2 stimulates human T cells at a lower (sixfold to 170-fold) efficiency. In contrast, the T cell stimulating activities of mouse and human B cell stimulatory factor 1 (interleukin 4; IL 4) appear to be species specific over the range of concentrations tested; we detected no activity of mouse IL 4 on human T cells, or human IL 4 on mouse T cells.

Animals↗

PubMed1986

Alterations in the amino-terminal third of mouse interleukin 2: effects on biological activity and immunoreactivity.

In this report, we describe plasmids that direct the expression of active mouse interleukin 2 (mIL 2) in Escherichia coli, and the use of this expression system to perform a mutational analysis of the N-terminal region of the mIL 2 protein. We found that the N-terminus was tolerant to the addition of a few amino acids, and even the addition of 20 amino acids resulted in only a modest decrease in activity of the protein. The bioactivity of mIL 2 as defined by its ability to sustain the proliferation of cloned T cells was also only minimally affected by deletion of up to 13 N-terminal amino acids, or of the entire poly-GLN stretch (amino acids 15-26). Deletion of the 30 N-terminal amino acids drastically reduced but did not abolish activity. Deletion of the 41 N-terminal amino acids completely abolished activity, whereas certain changes in the initial 37 amino acids drastically reduced the biological activity of the protein. We also analyzed the immunoreactivity of the mutant proteins with the anti-IL 2 monoclonal antibodies S4B6 and DMS-1. This analysis showed that the determinant recognized by S4B6 required that the N-terminal mIL 2 amino acids 26-45 be intact, whereas the DMS-1 determinant was located to the C-terminal side of amino acid 46.

Amino Acid Sequence↗

PubMed1986

Activation of mouse T-helper cells induces abundant preproenkephalin mRNA synthesis.

Antigenic or mitogenic stimulation of T cells induces the secretion of an array of protein hormones that regulate immune responses. Molecular cloning has contributed strongly to our present understanding of the nature of this regulation. A complementary DNA (cDNA) library prepared from a cloned concanavalin A-activated mouse T-helper cell line was screened for abundant and induction-specific cDNA's. One such randomly chosen cDNA was found to encode mouse preproenkephalin messenger RNA (mRNA). Preproenkephalin mRNA represented about 0.4 percent of the mRNA in the activated cell line but was absent in resting cells of this line. Other induced T-helper cell lines have 0.1 to 0.5 percent of their mRNA as preproenkephalin mRNA. Induced T-helper cell culture supernatants have [Met]enkephalin-immunoreactive material. The production by activated T cells of a peptide neurotransmitter identifies a signal that can potentially permit T cells to modulate the nervous system.

Animals↗

PubMed1986

Expression in Escherichia coli of synthetic human interleukin-1 alpha genes encoding the processed active protein, mutant proteins, and beta-galactosidase fusion proteins.

We have synthesized, cloned, and expressed the coding region for the C-terminal 159 amino acids (aa) of the human active interleukin polypeptide hormone IL-1 alpha. The sequence was assembled in stages and includes preferred Escherichia coli codons and unique restriction sites. The coding region was cloned on a multicopy plasmid vector adjacent to signals for transcription and translation that directed synthesis of 6% of total E. coli protein as IL-1 alpha. Active IL-1 alpha mutants that have a C-terminal additional eleven aa and that have N-terminal deletions of six and fourteen aa are described. Plasmids expressing beta-galactosidase fusion proteins with various parts of IL-1 alpha at their N-termini were constructed.

Base Sequence↗

PubMed1985

Structure of the Escherichia coli S10 ribosomal protein operon.

The complete structure of the Escherichia coli S10 ribosomal protein operon is presented. Based on the DNA sequence, the deduced order of the 11 genes in the operon is rpsJ, rplC, rplD, rplW, rplB, rpsS, rplV, rpsC, rplP, rpmC, rpsQ. The estimated transcribed length of the operon is 5181 base pairs. Putative sequences involved in ribosome binding are discussed. The DNA sequence data corrects several errors in previously determined protein sequence data.

Amino Acid Sequence↗