ABSTRACT
Two new systems for homogeneous plasma protein immunoassays, the Behring Nephelometer System and the Behring TurbiTimeSystem, as well as the Behring ELISA System for heterogeneous enzyme immunoassays are described.
Subject(s)
Blood Proteins/analysis , Computers , Enzyme-Linked Immunosorbent Assay/instrumentation , Immunoassay/instrumentation , Microcomputers , Nephelometry and Turbidimetry/instrumentation , Electronic Data Processing , Humans , SoftwareABSTRACT
Vertebrate and invertebrate L-lactate dehydrogenases (L-lactate:NAD+ oxidoreductase, EC 1.1.1.27) are effectively bound to oxamate-diaminohexyl-Sepharose, whereas several D-lactate dehydrogenases (D-lactate:NAD+ oxidoreductase, EC 1.1.1.28) do not bind to the same Sepharose. One explanation for our findings is that the enzymes' substrate is oriented in a reversed manner in the active center of the D- and L-lactate dehydrogenases.
Subject(s)
L-Lactate Dehydrogenase , Polysaccharides/metabolism , Sepharose/metabolism , Animals , Binding Sites , Chromatography, Affinity/methods , Horseshoe Crabs/enzymology , Isoenzymes , Isomerism , L-Lactate Dehydrogenase/metabolism , Nephropidae , Sepharose/analogs & derivatives , Substrate SpecificityABSTRACT
Recent observations of nonthermal, resonant biological responses to weak millimeter microwave irradiation have led us to investigate whether similar influences exist on enzymatic functions in vitro. We chose (i) the reduction of ethanol in the presence of alcohol dehydrogenase and (ii) the cooperative binding of oxygen on hemoglobin. Using an irradiation intensity near 10 mW/cm2 the frequency was continuously varied from 40 to 115 GHz with a resolution of a few MHz. No microwave influences were detectable within our experimental sensitivity of about 0.1% of the reaction rate in (i), or of the amount of bound oxygen at half saturation in (ii).
Subject(s)
Alcohol Oxidoreductases/radiation effects , Hemoglobins/radiation effects , Microwaves , Oxyhemoglobins/radiation effects , Humans , Saccharomyces cerevisiae/enzymologyABSTRACT
Modification of 17 from 24 lysine residues in pig heart lactate dehydrogenase (L-lactate: NAD+ oxidoreductase, EC 1.1.1.27) with methyl aceimidate yields an enzyme derivative with enhanced stability toward meat and alkaline denaturation as well as tryptic digestion. The specific activity of the modified enzyme is only slightly reduced
