Purification and Properties of Hog-Kidney 3,4-Dihydroxyphenylalanine Decarboxylase

Abstract

A procedure for the purification of 3,4-dihydroxyphenylaianine decarboxylase from hog kidney is described. Enzyme fractions with 190-fold greater specific activity than in the supernatant portion of kidney cortex have been obtained. Such fractions yield a single protein peak by disc gel electrophoresis and by continuous electrophoresis in acrylamide gel. The purified enzyme is partially resolved with respect to its coenzyme pyridoxal phosphate. It appears to consist of two polypeptide chains of unequal size. The purified enzyme catalyzes the decarboxylation of dihydroxyphenylalanine, 5-hydroxytryptophan, erythro-dihydroxyphenylserine, m-tyrosine, and o-tyrosine, but not of p-tyrosine and threo-dihydroxyphenylserine.

Inactivation of 3-(3,4-dihydroxyphenyl)alanine decarboxylase by 2-(fluoromethyl)-3-(3,4-dihydroxyphenyl)alanine

“…Coupled with the observed pyridoxal phosphate content, these data are consistent with enzyme being a dimer of two 53 000-56 000dalton subunits per molecule of coenzyme. These results agree favorably with the reported (Christensen et al, 1970) molecular weight of l 12 000 obtained by sedimentation equilibrium but differ from earlier reports of three (Christensen et al, 1970) subunits (57 000, 40000, and 21 000 daltons) and of two (Lancaster & Sourkes, 1972) subunits (48000-50000 and 40 000-44 000 daltons) observed on NaDodS04 gels. On native polyacrylamide gels purified enzyme usually displayed the previously described (Christensen et al, 1970) single broad band.…”

Purification and Characterization of 3,4‐Dihydroxyphenylalanine Decarboxylase from Pig Kidney

“…2), which shows a single symmetrical peak, with a sedimentation constant S~O , , , , equal to 6.1. From the same ultracentri- With a partial specific volume of 0.74 ml/g (calculated from the amino acid analysis [I] a molecular weight of 103000 results, which is close to the value of Christenson et al [l], and higher than that of Lancaster and Sourkes [2]. The coenzyme content of our preparation, determined as described elsewhere [9], ranges from 0.…”

“…[l] and Lancaster and Sourkes [2], it is characterized by a higher yield, it does not involve any heat treatment and makes use of exogenous coenzyme during the dialysis. This procedure yields an enzyme which appears to be homogeneous in polyacrylamide-gel electrophoresis and at least 95 % homogeneous in the ultracentrifuge.…”

“…2), which shows a single symmetrical peak, with a sedimentation constant S~O , , , , equal to 6.1. From the same ultracentri- Percentage of decarboxylation of 0.5 mM ~-3,4-dihydroxyphenyIalanine by different enzyme concentrations measured in the absence O'Leary and Baughn [4] of added pyridoxal-P (A) as Charteris and John [6] [2]. The coenzyme content of our preparation, determined as described elsewhere [9], ranges from 0.86 to 1.02 rnol of pyridoxal-P per 103 000 g of protein.…”

Trace Amines and Their Receptors

“…However, it should be borne in mind that AADC expression is not restricted to neuronal cells. AADC is present in a number of other cell types, including glia (Li et al, 1992b;Juorio et al, 1993), blood vessels , and cells of the gastrointestinal tract (Lauweryns and Van Ranst, 1988;Vieira-Coelho and Soares-da-Silva, 1993), kidney (Christenson et al, 1970;Lancaster and Sourkes, 1972;Aperia et al, 1990;Hayashi et al, 1990), liver (Bouchard and Roberge, 1979;Ando-Yamamoto et al, 1987;Dominici et al, 1987), lungs (Lauweryns and Van Ranst, 1988;Linnoila et al, 1993), pancreas (Lindström and Sehlin, 1983;Furuzawa et al, 1994;Rorsman et al, 1995), and stomach (Lichtenberger et al, 1982). In such cells, it can reasonably be expected that AADC will convert any precursor amino acids present into the corresponding trace amine(s).…”