Ceccherini-Silberstein Francesca, Erba Fulvio, Gago Federico, Bertoli Ada, Forbici Federica, Bellocchi Maria Concetta, Gori Caterina, D'Arrigo Roberta, Marcon Luisa, Balotta Claudia, Antinori Andrea, Monforte Antonella D'Arminio, Perno Carlo-Federico
Department of Experimental Medicine, University of Rome Tor Vergata, Italy.
AIDS. 2004 Aug 20;18(12):F11-9. doi: 10.1097/01.aids.0000131394.76221.02.
To define the extent of amino acid protease (PR) conservation in vivo in the absence and presence of pharmacological pressure in a large patient cohort.
Plasma-derived complete protein PR sequences from a well-defined cohort of 1096 HIV-1 infected individuals (457 drug-naive and 639 under antiretroviral therapy including PR-inhibitors) were obtained and analysed, and are discussed in a structural context.
In naive patients, the PR sequence showed conservation (< 1% variability) in 68 out of 99 (69%) residues. Five large conserved regions were observed, one (P1-P9) at the N-terminal site, another (E21-V32) comprised the catalytic active-site, a third (P44-V56) contained the flap, a fourth contained the region G78-N88, and another (G94-F99) contained the C-terminal site. In PR-inhibitor treated patients, the appearance of mutations primarily associated with drug resistance determined a decrease of amino acid invariance to 45 out of 99 residues (45% conservation). The overall degree of enzyme conservation, when compared to the PR sequences in drug-naive patients, was preserved at the N- and C-terminal regions, whereas the other large conserved areas decreased to smaller domains containing, respectively, the active-site residues D25-D29, the tip of the flap G49-G52, and the G78-P81 and G86-R87 turns.
Amino acid conservation in HIV PR can be minimally present in 45 residues out of 99. Identification of these invariable residues, with crucial roles in dimer stability, protein flexibility and catalytic activity, and their mapping on the three-dimensional structure of the enzyme will help guide the design of novel resistance-evading drugs.
在大量患者队列中，确定在不存在和存在药理压力的情况下，体内氨基酸蛋白酶（PR）的保守程度。
获取并分析了来自1096名HIV-1感染个体（457名未接受过治疗和639名接受包括PR抑制剂在内的抗逆转录病毒治疗）的明确队列的血浆来源的完整蛋白质PR序列，并在结构背景下进行了讨论。
在未接受过治疗的患者中，PR序列在99个残基中的68个（69%）显示出保守性（变异性<1%）。观察到五个大的保守区域，一个在N端位点（P1-P9），另一个（E21-V32）包含催化活性位点，第三个（P44-V56）包含瓣片，第四个包含G78-N88区域，另一个（G94-F99）包含C端位点。在接受PR抑制剂治疗的患者中，主要与耐药性相关的突变的出现使氨基酸不变性降低至99个残基中的45个（45%保守）。与未接受过治疗的患者的PR序列相比，酶的整体保守程度在N端和C端区域得以保留，而其他大的保守区域则减少为分别包含活性位点残基D25-D29、瓣片尖端G49-G52以及G78-P81和G86-R87转角的较小结构域。
HIV PR中的氨基酸保守性在99个残基中最少可有45个存在。鉴定这些在二聚体稳定性、蛋白质柔韧性和催化活性中起关键作用的不变残基，并将它们映射到酶的三维结构上，将有助于指导新型抗耐药药物的设计。
