Simsek S, Gallardo D, Ribera A, von dem Borne A E
Department of Immunological Haematology, Central Laboratory of the Netherlands Red Cross Blood Transfusion Service, Amsterdam.
Br J Haematol. 1994 Mar;86(3):671-4. doi: 10.1111/j.1365-2141.1994.tb04808.x.
GP Ia/IIa (also called VLA-2 or alpha 2 beta 1) is the primary receptor for collagen on platelets. The human platelet alloantigens HPA-5a(Brb) and HPA-5b(Bra) have been found to reside on the platelet GP Ia/IIa complex. In order to establish the molecular basis of the HPA-5 system, platelet RNA was isolated form HPA-5 (a+, b-) and HPA-5(a-, b+) individuals. After reverse transcription, cDNA coding for glycoprotein Ia (GP Ia) was amplified by the polymerase chain reaction (PCR). Nucleotide sequence analysis of the PCR products revealed an A-->G polymorphism at base pair 1648 of the coding region of the mature protein, resulting in a substitution of lysine (AAG) in HPA-5b(Bra) by glutamic acid (GAG) in HPA-5a(Brb) at amino acid 505. Subsequent PCR-ASRA (allele-specific restriction enzyme analysis) with Mnl I using cDNA derived from three HPA-5 (a+, b-), one HPA-5 (a+, b+) individuals demonstrated that HPA-5a and -5b alleles are distinguishable by DNA typing. In addition to the A-->G substitution at base pair 1648, three silent mutations were identified, G-->C (195 bp), C-->T (837 bp), G-->A (1041 bp).
糖蛋白Ia/IIa（也称为VLA-2或α2β1）是血小板上胶原蛋白的主要受体。已发现人类血小板同种异体抗原HPA-5a（Brb）和HPA-5b（Bra）存在于血小板糖蛋白Ia/IIa复合物上。为了确定HPA-5系统的分子基础，从HPA-5（a +，b-）和HPA-5（a-，b +）个体中分离出血小板RNA。逆转录后，通过聚合酶链反应（PCR）扩增编码糖蛋白Ia（GP Ia）的cDNA。对PCR产物的核苷酸序列分析显示，成熟蛋白编码区第1648个碱基对处存在A→G多态性，导致HPA-5b（Bra）中的赖氨酸（AAG）在氨基酸505处被HPA-5a（Brb）中的谷氨酸（GAG）取代。随后使用来自三名HPA-5（a +，b-）、一名HPA-5（a +，b +）个体的cDNA，用Mnl I进行PCR-ASRA（等位基因特异性限制酶分析），结果表明HPA-5a和-5b等位基因可通过DNA分型区分。除了第1648个碱基对处的A→G替换外，还鉴定出三个沉默突变，即G→C（195 bp）、C→T（837 bp）、G→A（1041 bp）。
