Natural Rubber and Structure of Latex, Biochemistry of

Wititsuwannakul, Dhirayos; Wititsuwannakul, Rapepun

doi:10.1002/3527600035.bpol2006

Cited by 14 publications

(14 citation statements)

References 96 publications

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“…The structure of Hevea latex and its detailed biochemistry has recently been thoroughly and extensively reviewed. [3] Fresh Hevea latex can simply be fractionated by centrifugation into three fractions as the top rubber layer, middle aqueous C serum, and the sediment bottom fraction (BF) of membrane-bound organelles. The BF content is quite considerable, constituting about 20 vol.-% [3] of the fresh latex as compared to an average of ca.…”

Section: Introductionmentioning

confidence: 99%

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Wititsuwaannakul

Rattanapittayaporn

Koyama

et al. 2004

Macromolecular Bioscience

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Centrifugation of fresh Hevea rubber latex yields three distinct fractions. The sediment bottom fraction (BF) content of membrane-bound organelles is ca. 20 vol.-% of latex. Prolonged storage or delayed use of fresh latex will result in disintegration and loss of the bottom fraction. This is due to the osmotically sensitive BF rupture and its membrane debris being tightly bound to the top rubber particles (RP) phase. The BF membrane was found to be highly active for rubber biosynthesis (RB), in contrast to previous reports that describe RB only occurring on the RP surface. It was clearly shown that washed BF membrane (WBM) was much more active than fresh RP for RB activity. WBM was highly activated by SDS for RB in a biphasic manner, but SDS strongly inhibited the RP. Probably WBM micelle formation resulted in a highly increased active surface area for RB. C55-PP (UPP) was a very active allylic for WBM in RB function, but inactive for RP. Serial acetone extraction of WBM proteins showed a distinct profile of the fractions with different RB activity. WBM isolated proteins suspended in 2% sodium dodecyl sulfate (SDS) with an RB activity equal to that of intact WBM was with the 20% acetone protein fraction. The 60 and 80% fractions were inactive. Combining the 20 with 80% fractions showed a complete inhibition of RB activity. Complete RB loss was also found when WBM was mixed with the 80% fraction, indicating that WBM has both an enzyme system and a factor for regulation of the RB activity in a well controlled metabolic function for the latex RB process.

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Section: Introductionmentioning

confidence: 99%

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Wititsuwaannakul

Rattanapittayaporn

Koyama

et al. 2004

Macromolecular Bioscience

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“…About 99% of the commercially used NR is produced by Hevea brasiliensis, originally native to Brazil (72). A potential alternative source of NR is the Russian dandelion (Taraxacum kok-saghyz).…”

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confidence: 99%

Historical and Recent Achievements in the Field of Microbial Degradation of Natural and Synthetic Rubber

Yikmis

Steinbüchel

2012

Appl Environ Microbiol

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This review intends to provide an overview of historical and recent achievements in studies of microbial degradation of natural and synthetic rubber. The main scientific focus is on the key enzymes latex-clearing protein (Lcp) from the Grampositive Streptomyces sp. strain K30 and rubber oxygenase A (RoxA) from the Gram-negative Xanthomonas sp. strain 35Y, which has been hitherto the only known rubber-degrading bacterium that does not belong to the actinomycetes. We also emphasize the importance of knowledge of biodegradation in industrial and environmental biotechnology for waste natural rubber disposal.

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“…Study on rubber biosynthesis (RB) process is of much interest and has appeared in several reviews. [3][4][5][6][7] The most extensive and up to date review covering most aspects of the Hevea latex structure and biochemistry [8] appeared recently with full details, discussions and the perspective outlooks. Decent understanding of the RB process is still ambiguous and the clear evidence has yet to be convincingly presented.…”

Section: Introductionmentioning

confidence: 99%

“…Hevea latex biochemistry was thoroughly reviewed recently. [8] Fresh Hevea latex can be fractionated into three fractions by centrifugation, the top rubber phase, aqueous C serum and bottom fraction (BF) of membrane-bound organelles. BF content is quite considerable, constituting about 20% by volume [8] compared to ca.…”

Section: Introductionmentioning

confidence: 99%

Significant Role of Bacterial Undecaprenyl Diphosphate (C₅₅‐UPP) for Rubber Synthesis by Hevea Latex Enzymes

Rattanapittayaporn

Wititsuwannakul

2004

Macromolecular Bioscience

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Washed bottom fraction (BF) membrane-bound particles of centrifuged fresh Hevea latex were found to be very active in rubber biosynthesis (RB). The washed BF membrane (WBM) showed higher RB activity and is strongly stimulated by anionic surfactants--more by DOC than SDS. WBM enzymes system can synthesize rubber either with allylic isoprenes (higher RB) or without (lower RB). Washed rubber particles (WRP), used generally in RB assays, had very low RB activity compared to the much higher activity observed for WBM. Bacterial undecaprenyl diphoshate (C(55)-UPP) was very active allylic initiator for rubber synthesis by WBM. Comparisons of allylic UPP with the shorter ones (C(15)-FPP, C(20)-GGPP) showed that UPP was the most effective. WBM activity orders were UPP >> GGPP > FPP. The DOC activated WBM synthesized less polyprenyl intermediates (butanol extractable) but more final rubber product (toluene/hexane extract), different than FPP and GGPP. WBM enzymes were highly versatile in using diverse different allylics, but UPP was most preferable. WRP was found a little active for UPP with DOC, but still much lower than WBM. Rubber product analysis by RP-TLC with acetone/hexane solvent system showed that WBM was mostly rubber, but WRP was mainly the intermediates. Quantitative analysis showed that WBM labeled rubber was confined to the origin spot, different than WRP as mainly labeled intermediates. It was thus confirmed that the WBM plays the key role in RB functions, and not WRP as mostly reported. WBM served as the actual rubber synthesis site, and bacterial UPP was very good RB initiator.

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Natural Rubber and Structure of Latex, Biochemistry of

Abstract: Introduction Historical Outline Discovery of Rubber and Improvement of Rubber Properties History of Rubber Trees and Rubber Plantations Latex of Hevea brasiliensis Composition of Hevea … Show more

Cited by 14 publications

References 96 publications

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Historical and Recent Achievements in the Field of Microbial Degradation of Natural and Synthetic Rubber

Significant Role of Bacterial Undecaprenyl Diphosphate (C₅₅‐UPP) for Rubber Synthesis by Hevea Latex Enzymes

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Natural Rubber and Structure of Latex, Biochemistry of

Abstract: Introduction Historical Outline Discovery of Rubber and Improvement of Rubber Properties History of Rubber Trees and Rubber Plantations Latex of Hevea brasiliensis Composition of Hevea … Show more

Cited by 14 publications

References 96 publications

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Involvement of Hevea Latex Organelle Membrane Proteins in the Rubber Biosynthesis Activity and Regulatory Function

Historical and Recent Achievements in the Field of Microbial Degradation of Natural and Synthetic Rubber

Significant Role of Bacterial Undecaprenyl Diphosphate (C55‐UPP) for Rubber Synthesis by Hevea Latex Enzymes

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Significant Role of Bacterial Undecaprenyl Diphosphate (C₅₅‐UPP) for Rubber Synthesis by Hevea Latex Enzymes