Crystallization and preliminary X-ray diffraction analysis of boar seminal plasma spermadhesin PSP-I/PSP-II, a heterodimer of two CUB domains

Antonio Romero,Paloma F Varela,Libia Sanz,Edda Töpfer-Petersen,Juan J Calvete

doi:10.1016/0014-5793(96)00133-0

Antonio Romero, Paloma F Varela + Show 3 more

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https://doi.org/10.1016/0014-5793(96)00133-0

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Abstract

Boar spermadhesin PSP-I/PSP-II ( M r 29 000–30 000), a non-covalent heterodimer of two CUB domains, was crystallized in two crystal forms. Complete diffraction data sets for hexagonal (space group P6 1,522) and trigonal (space group P3 1,221) crystals have been collected up to 2.9 and 2.5 Å resolution, respectively. Cell constants of the hexagonal and trigonal crystal forms are a=b=87.2 A ̊ , c=152.4 A ̊ , and a=b=96.2 A ̊ , c=70.8 A ̊ , respectively. The calculated packing parameters ( V m) are 2.8 and 3.2 Å 3/Da for the hexagonal and trigonal crystal forms, respectively, indicating that, in both cases, the asymmetric unit is constituted by one PSP-I/PSP-II heterodimer. This paper reports the first crystals of a protein built up by a CUB domain architecture.

Highlights

Porcine seminal plasma protein II (PSP-II) is a 14-16 kDa (116 amino acids) glycoprotein [1], which forms a non-covalent heterodimer with certain glycoforms of porcine seminal plasma protein (PSP)-I (109 residues, 14-16 kDa) [2]
The PSP-I/PSP-II complex is a major component of boar seminal plasma [3]
Spermadhesins are thought to play a pivotal role in aspects of porcine fertilization, i.e. sperm capacitation and sperm-egg interaction mediating the initial binding of spermatozoa to carbohydrate structures of glycoproteins of the extracellular matrix of the oocyte, the zona pellucida [4]

Summary

Introduction

Porcine seminal plasma protein II (PSP-II) is a 14-16 kDa (116 amino acids) glycoprotein [1], which forms a non-covalent heterodimer with certain glycoforms of PSP-I (109 residues, 14-16 kDa) [2]. Bovine, and equine spermadhesins share 40-98% amino acid sequence identity, contain two conserved disulphide bridges between nearest-neighbor cysteine residues, but do not No structural data of proteins containing CUB domains have been reported.

Results

Conclusion