Piet Wietzes

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The primary structure of human (Homo sapiens) pancreatic ribonuclease has been determined by automatic sequencing of the native protein and by analysis of peptides obtained by cleavage with proteolytic enzymes, cyanogen bromide, and hydroxylamine. The following sequence was deduced: (sequence in text). Human pancreatic ribonuclease differs at 37 positions(More)
The conversion of and toxic effects exerted by several mono- and dihalogenated C1 and C2 compounds on cultures of Xanthobacter autotrophicus GJ10 growing on 1,2-dichloroethane were investigated. Bromochloromethane, dibromomethane and 1-bromo-2-chloroethane were utilized by strain GJ10 in batch culture as a cosubstrate and sole carbon source. The rate of(More)
The influence of trichloroethylene (TCE) on a mixed culture of four different toluene-degrading bacterial strains (Pseudomonas putida mt-2, P. putida F1, P. putida GJ31, and Burkholderia cepacia G4) was studied with a fed-batch culture. The strains were competing for toluene, which was added at a very low rate (31 nmol mg of cells [dry weight] h). All four(More)
The primary structure of porcine pancreatic isophospholipase A2 (EC has been investigated. The sequence of procine isophospholipase differs from the sequence of porcine phospholipasy by four substitutions; viz. Ala12 leads to Thr; His17 leads to Asp leads to; Met20 leads to Leu and Glu71 leads to Asn.
Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades(More)
The phenylalanine aminomutase (PAM) from Taxus chinensis catalyses the conversion of alpha-phenylalanine to beta-phenylalanine, an important step in the biosynthesis of the N-benzoyl phenylisoserinoyl side-chain of the anticancer drug taxol. Mechanistic studies on PAM have suggested that (E)-cinnamic acid is an intermediate in the mutase reaction and that(More)
The N-terminal sequences of two calf-thymus non-histone chromosomal proteins, HMG-1 and HMG-2, are compared. Both N-terminal sequences are basic, and differ at only one position. This contrasts with the C-terminal portion of HMG-1 which we have previously shown to be high in acidic residues. There is no obvious sequence homology with any of the known(More)
The cellulose acetate electrophoretic pattern of the serum from patient Sik disclosed two distinct peaks, representing two monoclonal proteins. On immunoelectrophoresis the two M-components were found to differ in heavy chain class as well as in light chain type, IgG3(kappa) and IgA1(lambda). Serum immunoglobulin levels remained relatively constant over a(More)
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