Search PubMed⌕ Search

Biomedical subjects

D M Neville

Publications and source records attributed to D M Neville.

103 records · Page 6Linked to original sources
PubMed1971

Insulin receptors in the liver: specific binding of ( 125 I)insulin to the plasma membrane and its relation to insulin bioactivity.

With [(125)I]insulin at 7 x 10(-10) M, 25% of the radioactivity was bound to plasma membranes purified from rat liver. 20% of the [(125)I]insulin binding was inhibited by unlabeled insulin at 10(-9) M (6 ng/ml), equivalent to insulin concentrations in hepatic portal blood; inhibition of [(125)I]insulin binding was 80% at 10(-7) M and 90% at 10(-5) M. Eight insulins and derivatives with biological potencies that differed over a 100-fold range inhibited the binding of [(125)I]insulin to liver membranes in direct proportion to their ability to stimulate glucose oxidation in isolated fat cells. Inactive insulin chains, as well as glucagon, ACTH, and human growth harmone were without effect. The binding of [(125)I]insulin increased 55-fold as plasma membrane was purified from crude homogenate. Binding was time- and temperature-dependent, and addition of excess insulin produced rapid dissociation of [(125)I]insulin. This study demonstrates directly the binding of insulin to its biologically important receptors.

Adipose Tissue↗
PubMedDate not supplied

Genetic construction and characterization of an anti-monkey CD3 single-chain immunotoxin with a truncated diphtheria toxin.

We have previously developed a chemically conjugated anti-rhesus monkey CD3 immunotoxin FN18-CRM9 that can deplete in vivo T cells and induce long term tolerance of mismatched renal allograft in rhesus monkeys. This immunotoxin is a monkey analogue of anti-human CD3 immunotoxin UCHT1-CRM9. In this study, we cloned the light and heavy chain variable regions of anti-monkey CD3 monoclonal antibody FN18 and constructed a single-chain Fv (sFv) by linking variable light and variable heavy regions with a (Gly4Ser)3 linker. The single-chain immunotoxin DT390-FN18sFv was constructed by ligating the sFv to the carboxyl terminus of DT390, a truncated form of diphtheria toxin. The DT390-FN18sFv fusion protein was expressed in Escherichia coli and purified with Ni-RTA affinity and anion exchange columns. Similar to the chemically conjugated immunotoxin FN18-CRM9, DT390-FN18sFv can also specifically inhibit protein synthesis in primary monkey T cells in a dose-dependent manner. DT390-FN18sFv at 10(-7) mol/L or FN18-CRM9 at 10(-8) mol/L is sufficient to reduce protein synthesis of monkey primary T cells to less than 5% of the control. The 50% inhibition dosage (IC50) of FN18-CRM9 is 1 x 10(-10) mol/L, while the IC50 of DT390-FN18sFv is 1 x 10(-8) mol/ L, reflecting the lowered affinity of monovalent Fab' FN18 to its parental divalent antibody. The availability of functional FN18sFv will provide the basis for the construction of divalent anti-CD3 immunotoxins for preclinical studies on the induction of tolerance in organ transplantation and experimental autoimmune diseases.

Adenosine Diphosphate Ribose↗