The enzymatic synthesis of rubber polymer

Conference · Tue May 01 04:00:00 EDT 1990 · Plant Physiology, Supplement; (USA)

OSTI ID:5841796

Venkatachalam, K V; Wooten, L; Benedict, C R ^[1]

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1. Texas A M Univ., College Station (USA)

Washed rubber particles (WRP) isolated from stem homogenates of Parthenium argentatum by ultracentrifugation and gel filtration on columns of LKB Ultrogel AcA34 contain a tightly bound rubber transferase which catalyzes the polymerization of IPP into rubber polymer. The polymerization reaction requires Mg{sup 2+}, IPP and an allylic-PP. The Km values for Mg{sup 2+}, IPP and DMAPP are 5.2{times}10{sup {minus}4}M, 8.3{times}10{sup {minus}5} M and 9.6{times}10{sup {minus}5}M respectively. Gel permeation chromatography of the enzymatic polymer product on 3 linear columns of 1{times}10{sup 6} to 500 {angstrom} Ultrastyragel shows that the in vitro formed polymer has a similar mol wt to natural rubber. Over 90% of the in vitro formation of the rubber polymer was a de novo polymerization reaction from DMAPP initiator and IPP monomers. The bound rubber polymerase substantially differs from cytosolic rubber transferase which catalyzes only chain lengthening reactions. Treatment of the WRP with Chaps solubilized the bound rubber transferase which was further purified by DEAE-cellulose chromatography. The purified preparation primarily consists of a 52 kD polypeptide which binds to a photolabile substrate analog. The soluble rubber transferase catalyzes the synthesis of a 1{times}10{sup 5} mol wt rubber polymer from Mg{sup 2+}, DMAPP, IPP and detergent.

• OSTI ID: 5841796
• Report Number(s): CONF-9007196--
• Conference Information: Journal Name: Plant Physiology, Supplement; (USA) Journal Volume: 93:1
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
BIOCHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
ELASTOMERS
ENZYME ACTIVITY
ENZYMES
EUPHORBIA
GUAYULE
IN VITRO
KINETICS
MAGNOLIOPHYTA
MAGNOLIOPSIDA
NATURAL RUBBER
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PLANTS
POLYMERIZATION
POLYMERS
REACTION KINETICS
RUBBER TREES
RUBBERS
SYNTHESIS
TRANSFERASES
TREES