Aktiviti-aktiviti Penyelidikan
Kultur Tisu dan Transformasi Genetik
Teknik kultur tisu digunakan untuk memenuhi keperluan transformasi genetik di dalam Hevea brasiliensis. Turutan gen yang mengkodkan protein yang merujuk kepada ciri-ciri tertentu pokok getah telah dimasukkan secara in vitro ke dalam tisu kalus anter. Proses ini dibantu oleh bakteria (Agrobacterium). Kalus yang telah ditransformasikan secara genetik kemudiannya diregenerasikan menjadi anak pokok melalui kaedah tisu kultur.
Objektif utama bagi transformasi genetik adalah peningkatan produktiviti tanaman dengan cara memperbaiki ciri-ciri fisiologi yang terpilih bagi pokok getah. Terdapat dua ciri pokok getah yang mendapat manfaat dari proses transgenesis iaitu penambahan ukur lilit bagi penghasilan balak dan kerintangan terhadap penyakit terutamanya penyakit daun Agrobacterium.
Peranan kedua bagi pokok getah transgenik adalah penghasilan protein komersil di dalam lateks. Gen yang mengkodkan protein yang mengandungi nilai-nilai komersil dimasukkan ke dalam pokok getah dan kemudiannya pokok getah ini menjadi kilang semulajadi bagi penghasilan protein asing. Contohnya protein yang digunakan dalam bidang farmaseutikal dan produk kegunaan peribadi.Protein rekombinan yang disintesiskan di dalam lateks akan diekstrak secara terus menerus dan tanpa perlu memusnahkan pokok tersebut. Ini memandangkan proses ekstrak adalah dengan cara torehan. Pokok getah transgenik memerlukan penyelenggaraan yang mudah dan mesra alam berbanding sistem bioreaktor yang kini digunakan bagi menghasilkan produk farmaseutikal. Pokok getah transgenik bagi peringkat eksperimentasi dijalankan di Institut Penyelidikan Getah Malaysia telah berjaya menghasilkan enzim bakteria (GUS), antibodi tikus dan serum albumin manusia.
Salah satu aspek yang sedang dikaji di dalam transformasi genetik adalah tentang penggunaan gen promoter dari Hevea (turutan gen yang mengawal tindakan gen) yang berfungsi di dalam tisu spesifik pada pokok getah transgenik. Promoter yang spesifik bagi ekspresi gen di dalam lateks vesel adalah gen promoter hevein. Hevein adalah salah satu protein terbanyak yang terdapat di dalam lateks. Di dalam satu kajian, DNA bagi ekspresi protein GUS telah dicantum bersama promoter hevein dan digunakan di dalam transformasi genetik Hevea. Ekspresi GUS dapat dilihat di dalam embroid yang diperoleh.
Pokok getah transgenik
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Warna biru (kiri) pada pokok transformasi selepas tindakbalas dengan GUS substrate. Lateks dari pokok kawalan tidak berubah warna. |
Penerbitan
E. SUNDERASAN, and SITI ARIJA M. ARIF. Genetic transformation of rubber tree for the production of pharmaceuticals and improved agronomic traits. Paper presented at Seminar on Application of Transgenic Technology in Agriculture, 13 December 2010, UPM Serdang, Selangor.
YEANG, H.Y., AROKIARAJ, P., JAAFAR, H., ARIF, S.A.M., RAJAMANIKAM,
S., CHAN, J.L., SHARIB, J., LEELAVATHY, R., HAMZAH, S. and VAN DER LOGT, C.P.E.
(2002) Expression of a functional recombinant antibody fragment in the latex of
transgenic Hevea brasiliensis.
Journal of Rubber Research,
5(4),
215-25.
AROKIARAJ, P., RUEKER, F, OBERMAYR, E., SHAMSUL BAHRI, A.R.,
HAFSAH JAAFAR, CARTER, D.C. and YEANG, H.Y. (2002) Expression of human serum albumin
in transgenic Hevea brasiliensis.
Journal of Rubber Research,
5(3),
157-66.
AROKIARAJ, P., YEANG, H.Y., CHEONG, K.F., SAMSIDAR HAMZAH, JONES,
H. AND COOMBER, S. and CHARLWOOD, B.V. (1998) CaMV 35S promoter directs ß-glucuronidase
(GUS) expression in the laticiferous system of transgenic Hevea brasiliensis
(rubber tree). Plant Cell Reports, 17, 621-5.
AROKIARAJ, P., JONES, H., HAFSAH JAAFAR, COOMBER, S. and CHARLWOOD,
B.V. (1996) Agrobacterium-mediated transformation of Hevea anther calli
and their regeneration into plantlets. Journal of Natural Rubber Research,
11(2), 77-86.
Molecular Markers and Genetics
Molecular markers serve as useful aids in understanding the Hevea genetics, particularly in genotype selection and can hence facilitate and hasten the progress in breeding. Several molecular marker systems have been attempted in the genotyping H. brasiliensis, such as Restriction Fragment Length Polymorphism (RFLP), Random Amplified Polymorphic DNA (RAPD), DNA Amplified Fragments (DAF) and Amplified Fragment Length Polymorphism (AFLP). Among these, the AFLP system has been successful in producing a number of genetic maps of H. brasiliensis clones RRIM 937, RRIM 600, PB 5/51 and IAN 873. Meanwhile, Quantitative Trait Loci (QTL) map for susceptibility/resistance to the pathogenic fungus Corynespora cassiicola is currently underway. The genetic and QTL maps are being enhanced by the discovery of Single Nucleotide Polymorphisms (SNPs).
Publications
SAFIAH ATAN, SUHAILA DERAPI, LIZAWATI ISMAIL, NOR AINI AB. SHUKOR (2011). Screening of Hevea progenies (PB5/51 x IAN873) with two races of Corynespora cassiicola. Journal of Rubber Research, 14(2), 110-122.
SAFIAH ATAN and NOOR HISHAM HAMID (2003) Differentiating races
of Corynespora cassiicola using RAPD and internal transcribed spacer markers.
Journal of Rubber Research, 6(1), 58-64.
LEITCH, A.R., LIM,Y.K., LEITCH, I.J., O’NEILL, M., CHYE, M.L.
and LOW, F.C.(1998) Molecular cytogenetic studies in rubber Hevea brasiliensis
L. (Euphorbiaceae). Genome 41, 464-7.
YEANG, H.Y., SUNDERASAN, E., WICKNESWARI, R., NAPI, D. and ZAMRI,
A.S.M. (1998) Genetic relatedness and identities of cultivated Hevea clones
determined by isozymes. Journal of Rubber Research, 1(1),
35-47.
LOW, F.C., SAFIAH ATAN, HAFSAH JAAFAR and TAN, H. (1996) Recent
advances in the development of molecular markers for Hevea studies. Journal
of Natural Rubber Research, 11(1), 32-44.
SAFIAH ATAN, LOW, F.C. and SALEH, N..M. (1996) Construction of
a microsatellite-enriched library from Hevea brasiliensis. Journal
of Natural Rubber Research, 11(4), 247-55.
Penanda-penanda Molekul dan Genetik
Penanda-penanda molekul menyediakan panduan berguna mengenai genetik Hevea brasiliensis. Penanda-penanda molekul boleh memainkan peranan penting dalam pemilihan genotip dan justeru dapat membantu memudahkan dan mempercepatkan peningkatan dalam pembiakbakaan Hevea.
Prob-prob dan penanda-penanda DNA digunakan untuk pemetaan genetik dan pemetaan penanda-penanda, penetuan ciri-ciri dan pengesanan variasi somaklonal. Kini, tumpuan diberikan terhadap penggunaan Penggandaan Polimorfism Panjang Fragmen/Amplified Fragment Length Polymorphism (AFLP) untuk pemetaan lokus-lokus ciri-ciri kuantitatif (QTLs), pembinaan peta kaitan genetik, dan genotiping kultivar-kultivar getah yang memiliki ciri-ciri/sifat-sifat yang menghasilkan lateks-balak.
Penerbitan
SAFIAH ATAN and NOOR HISHAM HAMID (2003) Differentiating races
of Corynespora cassiicola using RAPD and internal transcribed spacer markers.
Journal of Rubber Research, 6(1), 58-64.
LEITCH, A.R., LIM,Y.K., LEITCH, I.J., O’NEILL, M., CHYE, M.L.
and LOW, F.C.(1998) Molecular cytogenetic studies in rubber Hevea brasiliensis
L. (Euphorbiaceae). Genome 41, 464-7.
YEANG, H.Y., SUNDERASAN, E., WICKNESWARI, R., NAPI, D. and ZAMRI,
A.S.M. (1998) Genetic relatedness and identities of cultivated Hevea clones
determined by isozymes. Journal of Rubber Research, 1(1),
35-47.
LOW, F.C., SAFIAH ATAN, HAFSAH JAAFAR and TAN, H. (1996) Recent
advances in the development of molecular markers for Hevea studies. Journal
of Natural Rubber Research, 11(1), 32-44.
SAFIAH ATAN, LOW, F.C. and SALEH, N..M. (1996) Construction of
a microsatellite-enriched library from Hevea brasiliensis. Journal
of Natural Rubber Research, 11(4), 247-55.
Fisiologi, Biokimia dan Biologi Molekul Tumbuhan
Dalam kajian biokimia dan pengawalaturan pada peringkat sel dan keseluruhan pokok Hevea, fokus diberikan terhadap mekanisme pengawalan penghasilan getah. Aspek-aspek molekul, biokimia dan selular enzim-enzim penting yang mengawalatur biosintesis getah telah difahami. Kebanyakan kajian terkini telah tertumpu kepada fungsi protein-protein aruhan dan protein-protein penyekat yang mempengaruhi kadar biosintesis getah. Kajian juga dijalankan terhadap pemencilan, pengekspresan dan pencirian gen-gen daripada tapak jalan pengisyaratan etilina. Gen-gen tersebut penting dalam pengawalaturan fisiologi pengaliran lateks apabila pokok getah ditoreh.
Satu lagi kajian yang mendapat perhatian adalah bidang tag jujukan terungkap [Expressed sequence tag EST)]. Jujukan-jujukan pendek DNA yang dipencilkan daripada lateks memberi gambaran tentang gen-gen yang terungkap di dalam lateks. Gen-gen yang diminati untuk kajian pada masa hadapan boleh dipencilkan menggunakan tag-tag jujukan terungkap ini sebagai panduan jujukan-jujukan gen. Katalog gen-gen ini akan menjadi penting dalam kajian fungsi gen dan pengawalaturan genetik fisiologi dan biokimia Hevea. Sebagai contoh, satu jujukan gen yang mengekod enzim dari langkah yang dianggap sebagai tapakjalan biosintesis getah alternatif telah dikenalpasti daripada koleksi EST lateks MRB dan kajian mengenai gen ini sedang dijalankan.
Penerbitan
SUNDERASAN, E., LING, S.K., SITI ARIJA MAD ARIF AND YEANG, H.Y. (2007) Deciphering Rubber Particle Destabilisation by Hevea Bark Extract. J Rubb Res 10(2) 89-98.
CHOW, K.S., WAN, K.L., ISA, M.N.M., BAHARI, A., TAN, S.H., HARIKRISHNA, K. AND YEANG, H.Y. (2007) Insights into rubber biosynthesis from transcriptome analysis of Hevea brasiliensis latex. J. Exp. Bot. 58(10): 2429–2440.
KENG-SEE CHOW, FARIDAH YUSOF, SALIMAH MOHD. LIM AND LATIFAH ABDULLAH
(2006). An Assessment of Stimulation of Hevea brasiliensis Rubber Biosynthesis
by eIF-5A Protein-enriched Bacterial Lysates.
Journal of Rubber Research 9(4):
251-259.
AROKIARAJ, P. AND YEANG H.Y. (2006) Yield stimulation of the rubber tree (RRIM 600)
with Ethephon does not increase Latex Hev b6 Protein or mRNA.
Journal of Rubber Research 9(1), 61-71.
PUJADE-RENAUD, V., SANIER, C., CAMBILLAU, L., PAPPUSAMY, A.,
JONES, H., RUENGSRI, N., CHRESTIN, H., THARREAU, D., MONTORO, P. AND NARANGAJAVANA,
J. (2005) Molecular characterisation of new members of the Hevea brasiliensis
hevein multigene family and analysis of their promoter region in rice.
Biochimica et Biophysica Acta,1727(3),151-61.
YEANG, H.Y. (2005) The kinetics of latex flow from the rubber
tree in relation to latex vessel plugging and turgor pressure.
Journal of Rubber Research, 8(3), 160-81
KO, J.H., CHOW, K.S. and HAN, K.H. (2003) Transcriptome analysis
reveals novel features of the molecular events occurring in the laticifers of Hevea
brasiliensis (para rubber tree).
Plant Molecular Biology,
53(4),
479-92.
K.-S. CHOW, SALIMAH M. LIM and K.-H. HAN (2003) Characterisation
of a family of eIF-5A cDNAs from Hevea brasiliensis.
Journal of Rubber Research,
6(2),
107-120.
SUNDERASAN, E., WARD, M.A. and YEANG, H.Y. (2002) Isolation and characterisation
of latex cyanogenic glucosidase.
Journal of Rubber Research,
5(4),
244-52.
SIVAKUMARAN, S., GHANDIMATHI, H., ZAINAB HAMZAH, FARIDAH YUSOF, SAMSIDAR HAMZAH
and YEANG, H.Y. (2002) Physiological and nutritional aspects in relation to the
spontaneous development of tapping panel dryness in clone PB 260.
Journal of Rubber Research,
5(3),
135-56.
BOKMA, E., SPIERING, M., CHOW, K.S., MULDER, P.M.F., SUBROTO, T. and BEINTEMA, J.J.
(2001). Determination of cDNA and genomic DNA sequences of hevamine, a chitinase
from the rubber tree Hevea brasiliensis. Plant Physiology
and Biochemistry, 39, 367-76.
YUSOF, F., CHOW, K.S., WARD, M. and WALKER, J.M. (2000) A stimulator
protein of rubber biosynthesis from Hevea brasiliensis latex,
Journal of Rubber Research, 3(4), 193-210.
LUO, S., XIAO, X., HAMZAH, S. and YEANG, H.Y. (2000) Hev
b3 in latex from TPD rubber trees. Chinese Journal of Tropical Crops,
21(2), 7-11.
SAMSIDAR HAMZAH, XIAO, X., LUO, S., CHAN, J.L. and YEANG, H.Y.
(2000) Protein marker for tapping panel dryness identified as the small rubber particle
protein (Hev b 3). Journal of Rubber Research, 3(1),
42-52.
HAN K.H., SHIN D.H., YANG J., KIM I.J., OH S.K. and CHOW K.S.
(2000) Genes expressed in latex of Hevea brasiliensis. Tree Physiology,
20, 503-510.
SHIN, D.H., YANG, J., CHOW, K.S. and HAN, K.H. (1999) A Hevea
brasiliensis homolog of DnaJ (HvDnaJ) is expressed abudantly in latex and
induced by ethylene (Accession No. AF085275) (PGR99-004). Plant Physiology
119, 363.
CHOW, K.S. (1999) Cloning of a thioredoxin h cDNA from Hevea
brasiliensis (Accession No. AFF133127) (PGR99-059). Plant Physiology
120:339.
OH, S.K., KANG, H., SHIN, D.H., YANG, J., CHOW, K.S., YEANG,
H.Y., WAGNER, B., BREITENEDER, H. and HAN, K.H. (1999) Isolation, characterisation
and functional analysis of a novel cDNA clone encoding a small rubber particle protein
from Hevea brasiliensis. Journal of Biological Chemistry
274(24):17132-8.
FARIDAH YUSOF, AUDLEY, B.G., ISMAIL, F. and WALKER, J.M. (1998)
A rapid assay for the incorporation of isopentenyl diphosphate in rubber biosynthesis.
Journal of Rubber Research, 1(1), 48-66.
FARIDAH YUSOF, WARD, M.A. and WALKER, J.M. (1998) Purification
and characterisation of an inhibitor of rubber biosynthesis from C-serum of Hevea
brasiliensis latex, Journal of Rubber Research, 1(2),
95-110.
SHAMSUL BAHRI, A.R. and SAMSIDAR HAMZAH (1996) Immunocytochemical
localisation of rubber membrane protein in Hevea latex. Journal of Natural
Rubber Research, 11(2), 88-95.
YEANG, H.Y. and OTHMAN HASHIM (1996) Destabilisation of lutoids
in Hevea brasiliensis latex during early and late flow. Journal
of Natural Rubber Research, 11(1), 45-58.
FARIDAH YUSOF, M.A. SITI ARIJA, GHANDIMATHI, H., ZAINAB HAMZAH,
SIVAKUMARAN, S. and YEANG, H.Y. (1995) Changes in some physiological latex parameters
in relation to the onset of induced tapping panel dryness. Journal of Natural Rubber
Research, 10(3), 182-98.
YEANG, H.Y., YIP, E. and SAMSIDAR HAMZAH (1995) Characterisation
of Zone 1 and Zone 2 rubber particles in Hevea brasiliensis latex.
Journal of Natural Rubber Research, 10(2), 108-23.
Biologi Pembiakkan
Penambahbaikan berterusan dalam produktiviti pokok getah, dari segi pengeluaran lateks dan kayu adalah kesan dari kerja-kerja pembiakan dan pemilihan.
Dalam pembiakkan Hevea, pendebungaan tiruan memainkan peranan penting dalam menghasilkan kultivar lebih baik dan baru.
Bagaimanapun, masalah pendebungaan di antara kultivar berlainan adalah penting dalam penyelidikan pembiakkan. Siasatan ke dalam biologi pembiakkan
pokok getah bertujuan untuk mengurangkan sebahagian masalah ini.
Mikrograf Pendafluor tiub debunga Hevea (t) menembusi ovul (o).
Penerbitan
HAMZAH S., CHAN, J.L. and YEANG, H.Y. (2002) Pollen tube growth
and fruit-set success in Hevea brasiliensis hand-pollination influenced
by the choice of clone and female flower.
Euphytica,
123,
1-8.
YEANG, H.Y. and CHEVALLIER, M.H. (1999) Range of Hevea
brasiliensis pollen dispersal estimated by esterase isozyme markers. Annals
of Botany, 84, 681-4.
SAMSIDAR HAMZAH, CHAN, J.L. and YEANG, H.Y. (1999) Hevea
brasiliensis seedlings from hand-pollination using cryo-stored pollen validated
by isozymes. Journal of Rubber Research, 2(1), 62-8.
SAMSIDAR HAMZAH and CHAN, J.L. (1996) Pollen storage of Hevea.
Journal of Natural Rubber Research, 11(2), 115-24.
Alergi Latex
Latex digunakan didalam pembuatan pelbagai barang-barang latex, di mana yang paling penting adalah produk-produk yang berkaitan dengan kesihatan/ kebersihan seperti sarung tangan getah. Terdapat banyak lapuran sejak 1990an mengenai protein-protein yang dijumpai di dalam sarung tangan getah dan alat-alat bantuan pembedahan yang diperbuat dari latex yang menyebabkan alergi pada orang-orang yang sangat peka. Oleh itu masaalah alergi latex melibatkan pengeluar-pengeluar dan juga pengguna-pengguna barangan latex.
Untuk menyelesaikan masaalah alergi latex, usaha telah dibuat untuk mengesan saki-baki protin di dalam barangan latex dan memahami sifat-sifat protin-protin saki-baki ini. Penyelidikan berterusan sedang di jalankan bagi mengasingkan, menulinkan dan mengenalpasti protin-protin alergenik spesifik dan mengklon gen-gen (cDNA) yang mengekod mereka. Apabila alergen-alergen tersebut telah dikenalpasti, maka adalah mungkin untuk mengembangkan diagnostik untuk alergi latex, immunoterapi untuk melegakan kesan-kesan alergi latex dan imunoasai untuk mengawal kualiti sarung tangan yang dikeluarkan.
Elektroforesis dua-dimension protin-protin sarung tangan getah yang
bertindakbalas dengan antiserum arnab terhadap protin-protin yang sama
Alergen-alergen Latex
Terdapat 13 alergen latex (protin-protin yang menyebabkan tindakbalas alergi) yang di iktiraf oleh tatanama badan dunia “International Union of Immunological Societies and the World Health Organisation”.
Penerbitan
A. MALIK, SITI ARIJA M. ARIF, S. AHMAD AND E. SUNDERASAN. (2008) A molecular and in silico characterisation of Hev b 4, a glycosylated latex allergen. Int. J. Biol. Macromolecules. 42(2) 185-190.
Yeang H.Y., S.A.M. Arif, Loke Y.H., Chew N.P. and Mohsin S.M. (2007) Electrophoretic Characterisation of Hevein. J. Rubb. Res. Vol 10(4), 2007, p. 235-244.
M. RAULF-HEIMSOTH, HP RIHS, P. ROZYNEK, R. CREMER, A. GASPAR, G. PIRES, H.Y. YEANG, S.A.M. ARIF, R.G. HAMILTON, I. SANDER, M. LUNDBERG, T. BRÜNING (2007) Quantitative analysis of IgE reactivity profiles in patients allergic or sensitized to natural rubber latex (Hevea brasiliensis). Clin Exp Allergy; 37 (11); 1657-67.
SMITH AM, AMIN HS, BIAGINI RE, HAMILTON RG, ARIF SA, YEANG HY AND BERNSTEIN DI (2007) Percutaneous reactivity to natural rubber latex proteins persists in health-care workers following avoidance of natural rubber latex. Clin Exp Allergy; 37 (9); 1349-56.
S. WAGNER, M. BUBLIN, C. HAFNER, T. KOPP, D. ALLWARDT, U. SEIFERT, S.A. ARIF, O. SCHEINER AND H. BREITENEDER (2007). Generation of Allergen-Enriched
Protein Fractions of Hevea brasiliensis Latex for in vitro and in vivo Diagnosis Int Arch Allergy Immunol 2007 , 143 : 246–254
YEANG, H.Y., HAMILTON, R.G., BERNSTEIN, D.I., ARIF, S.A.M., CHOW, K.S., LOKE, Y.H.,
RAULF HEIMSOTH, M., WAGNER, S., BREITENEDER, H., BIAGINI, R.E. (2006) Allergen concentration
in natural rubber latex. Clinical and Experimental Allergy 36, 1078-1086.
ARIF, S.A.M., HAMILTON R.G. AND YEANG, H.Y. (2006) IgE antibody
binding to the carbohydrate moiety of Hev b 13, Journal of Rubber Research 9(1) , 40-49.
KOLARICH, D, ALTMANN, F. AND SUNDERASAN, E. (2006) Structural
analysis of the glycoprotein allergen Hev b 4 from natural rubber latex by mass
spectrometry. Biochimica et Biophysica Acta , 1760(4), 715-20.
SUNDERASAN, E., BAHARI, A., ARIF, S.A.M., ZAINAL, Z., HAMILTON, R.G., and YEANG,
H.Y. (2005) Molecular cloning and immunoglobulin E reactivity of a natural rubber
latex lecithinase homologue, the major allergenic component of Hev b 4. Clinical and Experimental Allergy , 35, 1490-5.
KURUP, V.P., SUSSMAN, G.L., YEANG, H.Y., ELMS, N., BREITENEDER, H., ARIF, S.A.M.,
KELLY, K., BANSAL, N.K. and FINK, J.N. (2005) Specific IgE response to purified
and recombinant allergens in latex allergy. Clin Mol Allergy , 3, 11.
JOHAR, A., LIM, D., ARIF, S.A.M., HAWARDEN, D., DU TOIT, G., WEINBERG, E.G., MOTALA,
C., FIEGGEN, G., YEANG, H.Y. and POTTER, P.C. (2005) Low prevalence of latex sensitivity
in South African spina bifida children in Cape Town. Pediatric Allergy and Immunology,16(2), 165-70.
YEANG, H.-Y. and CHOW, K.-S. (2004) DNA cloning of Hev b 2 (Hevea latex ß-1,3-glucanase)
and IgE reactivity of the recombinant protein. Journal of Rubber Research 2004 7(3) :180-7.
YEANG, H.-Y., ARIF, S.A.M., RAULF-HEIMSOTH, M., LOKE, Y.-H., SANDER, I., SULONG,
S.H., LAU, C.-H., and HAMILTON, R.G. (2004) Hev b 5 and Hev b 13 as allergen markers
to estimate the allergenic potency of latex gloves. Journal of Allergy and Clinical Immunology , 114(3) , 593-8.
ARIF, S.A.M., HAMILTON, R.G., YUSOF, F., CHEW, N.-P., LOKE, Y.-H., NIMKAR, S., BEINTEMA,
J.J. and YEANG, H.Y. (2004) Isolation and characterisation of the Early Nodule Specific
Protein homologue (Hev b 13), an allergenic lipolytic esterase from Hevea brasiliensis latex.
Journal of Biological Chemistry, 279(23) :23933-41.
YEANG, H.Y. (2004) Natural rubber latex allergens: new developments, Current Opinion in Allergy & Clinical Immunology , 4(2) , 99-104.
BERNSTEIN, D.I., BIAGINI, R.E., KARNANI, R., HAMILTON, R , MURPHY, K., BERNSTEIN,
C., ARIF, S. A.., BRENDTS, B. and YEANG, H.Y. (2003) In vitro sensitization
to purified Hevea brasiliensis proteins in health-care workers sensitized
to natural rubber latex. Journal of Allergy and Clinical Immunology , 111(3) , 610-6.
YEANG, H.Y., LAU, C.H., SITI ARIJA M. ARIF, LOKE, Y.H., CHAN, J.L., SAMSIDAR HAMZAH
and HAMILTON, R.G. (2002) Hev b 1, Hev b 2 and Hev b 3 Contents in Natural Rubber
Latex and Powdered Latex Gloves. Journal of Rubber Research , 5(3), 167-78.
YEANG, H.Y., ARIF, S.A.M., YUSOF, F. and SUNDERASAN, E. (2002) The allergenic proteins of natural rubber latex.
Methods. 27(1) , 32-45.
IKRAM, A., BAHRI, A.R.S., FAUZI, M.S. and NAPI, N. (2001) Effects
of added nitrogen and phosphorus on the biodegradation of NR gloves in soil. Journal of Rubber Research , 4 , 102-17.
YEANG, H.Y., CHOW, K.S., YUSOF, F., ARIF, S.A.M., CHEW, N.P.
and LOKE, Y.H. (2000) Appraisal of latex glove proteins in the induction of sensitivity
to multiple latex allergens. Journal of Investigational Allergology & Clinical
Immunology , 10(4) , 215-22.
YEANG, H.Y. (2000) Prevalence of latex allergy may be vastly
over-estimated when determined by in vitro assays. Annals of Allergy , Asthma & Immunology , 84 , 628-32.
KURUP,V.P., YEANG, H.Y., SUSSMAN, G.L., BANSAL, N.K, BEEZHOLD,
D.H., KELLY, K.J., HOFFMAN, D.R., WILLIAMS, B. and FINK, J.N. (2000) Detection of
IgE in the sera of patients using purified latex allergens. Clinical and Experimental Allergy , 30(3) , 359-69.
JOHNSON, B.D., KURUP, V.P., SUSMAN, G.L., ARIF, S.A.M., KELLY,
K.J., BEEZHOLD, D.H. and FINK, J.N. (1999) Purified and remcombinant latex proteins
stimulate peripheral blood lymphocytes of latex allergic patients. International
Archives of Allergy and Immunology , 120 , 270-9.
WAGNER, B., KREBITZ, M., BUCK, D., NIGGEMANN, B., YEANG, H. Y.,
HAN, K.H., SCHEINER, O., and BREITENEDER, H. (1999). Cloning, expression and characterisation
of recombinant Hev b 3, a Hevea brasiliensis protein
associated with latex allergy in spina bifida patients. Journal of Allergy and Clinical Immunology. 104(5) , 1084-92.
SOWKA, S., HAFNER, C., RADAUER, C., FOCKE, M., BREHLER, R., ASTWOOD,
J. D., ARIF, S. A., KANANI, A., SUSSMAN, G. L., SCHEINER, O., BEEZHOLD, D. H., and
BREITENEDER, H. (1999). Molecular and immunological characterisation of new isoforms
of the Hevea brasiliensis latex allergen Hev b 7: Evidence
of no cross-reactivity between Hev b 7 isoforms and potato patatin and
proteins from avocado and banana. Journal of Allergy and Clinical Immunology , 104 , 1302-10.
AIRENNE, K.J., LAITINEN, O.H., ALENIUS, H., MIKKOLA, J., KALKKINEN,
N., ARIF, S.A., YEANG, H.Y., PALOSUO, T. and KULOMAA, M.S. (1999) Avidin is a promising
tag for fusion proteins produced in baculovirus-infected insect cells. Protein Expression and Purification , 17(1) ,139-45.
YEANG, H.Y., FARIDAH YUSOF and LATIFAH ABDULLAH (1998) Protein
purification for the Lowry assay: Acid precipitation of proteins in the presence
of SDS and other biological detergents, Analytical Biochemistry , 265 ,
381-384.
YEANG, H.Y., WARD, M.A., ZAMRI, A.S.M., DENNIS, M.S. and LIGHT,
D.R. (1998) Sequence similarity of Hev b 3 with two previously reported
27 and 23 kDa latex allergens detected by spina bifida patients. Allergy 53(5) , 513-9.
SOWKA, S. WAGNER, S., KREBITZ, M., SITI ARIJA MAD ARIF, FARIDAH
YUSOF, KINACIYAN, T., BREHLER, R., SCHEINER, O. and BREITENEDER, H. (1998) cDNA
cloning of the 43-kDa latex allergen Hev b 7 with sequence similarity to
patatin and its expression in the yeast Pichia pastoris . European Journal
of Biochemistry , 255 , 213-9.
YEANG, H.Y., CHEONG, K.F., SUNDERASAN, E., SAMSIDAR HAMZAH, CHEW,
N.P., SHARIFAH HAMID, HAMILTON, R.G. and CARDOSA, M.J. (1996) The 14.6kd rubber
elongation factor ( Hev b 1) and 24 kd ( Hev b 3 rubber particle
proteins are recognised by IgE from patients with spina bifida and latex allergy. Journal of Allergy and Clinical Immunology , 98(3) , 628-39.
SUNDERASAN, E., SAMSIDAR HAMZAH, SHARIFAH HAMID, WARD, M.A.,
YEANG, H.Y. and CARDOSA, M.J. (1995) Latex B-serum -1,3-glucanase ( Hev b
II) and a component of the microhelix ( Hev b IV) are major latex allergens. Journal of Natural Rubber Research , 10(2) , 82-99.
YEANG, H.Y., SUNDERASAN, E. and HAFSAH MOHD. GHAZALY (1995) Latex
allergy studies: Extraction of natural rubber latex proteins with reference to film
thickness, latex d.r.c. and protein migration behaviour. Journal of Natural Rubber Research , 10(1) , 46.
YEANG, H.Y., FARIDAH YUSOF and LATIFAH ABDULLAH (1995) Precipitation
of Hevea brasiliensis proteins with trichloroacetic acid and phosphotungstic
acid in preparation for the Lowry protein assay. Analytical Biochemistry , 226 , 35-43.