A novel receptor protein tyrosine kinase named ork (orphan receptor tyrosine kinase) is identified and characterized. cDNA encoding the ork protein is inserted into an expression vector for production of the protein via recombinant DNA technology. The ork cDNA, when transfected into Cos-7 cells, encodes a 140 Kd protein with in vitro kinase activity. The ork gene is expressed predominantly in placenta and lung, with lower levels in umbilical vein endothelial cells, brain and kidney.

Purified thymidine kinase is recovered from its contaminated aqueous solutions by adsorption on cross-linked dextran of chromatographic grade activated with bromine cyanide and coupled with 3'- or 5'-aminothymidine or its N-aminoalkyl derivatives, followed by elution with dilute sodium chloride solution at pH 8.

A shortened PGK promoter ranging from 165 to 404 base pairs of the Saccharomyces PGK promoter is taught. The promoter is operably linked to heterologous genes and improves the expression thereof relative to the full length PGK promoter.

A reagent system for assaying creatine kinase is disclosed. The reagent system consisting essentially of a first reagent comprising glucose-6-phosphate dehydrogenase, .beta.-nicotinamideadenine dinucleotide (phosphate), and adenosine diphosphate, and a second reagent comprising creatine phosphate, said second reagent being maintained at a pH of from 7.5 to 10, and at least one of said first reagent and said second reagent containing glucokinase and glucose. The creatine kinase-assaying reagent e...

Control serum containing a defined content of creatine kinase comprising exogeneous creatine kinase in the form of swine serum and optionally additionally comprising human serum, other animal serum or serum albumin; and/or other enzyme substrates and metabolites occurring in serum.

A reagent for the determination of creatine kinase is comprised of a reagent group containing N-acetylcysteine and ethylenediaminetetraacetic acid and a reagent group containing magnesium, whereby the stability thereof is acheived.

The present invention provides a process for stabilizing creatine kinase by disulphide modification, wherein creatine kinase is reacted in any desired sequence (a) with a molar excess of disulphide and/or thiosulphonate and (b) with a molar excess of water-soluble carbohydrate as carrier.

Disclosed are a novel cytoplasmic tyrosine kinase which is increased with respect to expression amount thereof in accordance with the differentiation of blood cells, and a deoxyribonucleic acid (DNA) coding for the same. The tyrosine kinase of the present invention can be advantageously used for screening chemical substances having the capability to inhibit or activate the tyrosine kinase activity of at least the tyrosine kinase of the present invention. Also disclosed are a replicable recombina...

The invention provides novel methods and compositions for detecting kinase activity in solution, without the use of radioactivity. The methods marry the kinetic advantages of solution-based reaction with the efficiency and high-throughput adaptability of solid-phase wash and detection steps, yet is conveniently practiced in a single tube. The methods may be used to assay for kinase activity per se or, by controlling for the kinase activity, for modulators of kinase activity. The method is exempl...

Tyrosine kinase mutant and wild-type genes useful in screening compositions which may affect DNA double-strand break repair activity.