A general method for relieving substrate inhibition in lactate dehydrogenases

The lactate dehydrogenases of hemopoietic cells.

By W. H. STARKWEATHER, H. H. SPENCER AND H. K. ScriocH M AMMALIAN LACTATE DEHYDROGENASE ( LDH ) can be separated into five active fractions.’4 The production of electrophoretic extremes, LDH-1 (H4 ) and LDH-5 ( M4 ), is controlled by the action of two genes.5’#{176}The intermediate fractions ( LDH-2, LDH-3, LDH-4 ) are considered hybrid forms of LDH-1 and LDH-5.5’” Assuming that the hybrids are...

Subunit hybridization of higher plant lactate dehydrogenases

developed a procedure, based on the affinity of all three enzymes for Cibacron Blue 3GA, which allows their simultaneous purification from a cell extract. E. coli K 12, EMG-2 was grown, harvested and disrupted as described by Miller & Stadtman (1972). After treatment with 1% (w/v) streptomycin sulphate, the cell extract was subjected to ammonium sulphate fractionation. The protein fraction prec...

Biochemical properties of trypanosomatid lactate dehydrogenases.

Lactate dehydrogenase (LDH, E.C.1.1.1.27) was found in supernatant (cytoplasmic enzyme) fractions of the trypanosomatid flagellates Trypanosoma conorhini and Crithidia fasciculata if 10 mm cysteine was present in the homogenizing medium. The T. conorhini LDH activity with pyruvate as substrate was increased 35% if 5 mm cysteine was also included in reaction mixtures. K(m) values for the T. cono...

A general method for determining secondary active transporter substrate stoichiometry

The number of ions required to drive substrate transport through a secondary active transporter determines the protein's ability to create a substrate gradient, a feature essential to its physiological function, and places fundamental constraints on the transporter's mechanism. Stoichiometry is known for a wide array of mammalian transporters, but, due to a lack of readily available tools, not ...

Intraperitoneal Dexamethasone As A New Method for Relieving Postoperative Shoulder Pain after Gynecologic Laparoscopy