BSA Cell Culture Grade Grade 35% BSA Liquid

PROPERTIES

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Albumin-based Stationary Phases

BSA and HSA are closely related proteins and, consequently, the chromatographic properties of the chiral stationary phases based on these proteins are similar. Sometimes the elution order is reversed between chiral stationary phases based on these proteins; on the HSA-based phases (S)-warfarin elutes before (R)-warfarin, whereas on the BSA-based phases the opposite elution order is observed.

Enantioselectivity of stationary phases based on BSA produced with isolated protein fragments has been investigated. The BSA fragment following peptic digest of BSA has molecular weights of about 35 kDa which is an N-terminal half of amino acid residues 1–307. The BSA fragment phases give longer retentions for benzoin and benzodiazepines, and higher enantioselectivity for lorazepam, benzoin and fenoprofen because of a higher density of chiral recognition site(s), compared with native BSA phases.

shows chromatograms of lorazepam enantiomers on BSA and BSA fragment-based columns. However, it is plausible that the conformation of the BSA fragment might be different from that of the native BSA.

 Acrosome reaction induced by neoglycoproteins containing Man and GlcNAc

Several BSA-based ‘neoglycoproteins’ were shown to stimulate the acrosome reaction. The binding of Man,Flu-BSA results in a time-dependent receptor aggregation and the induction of acrosome exocytosis in capacitated sperm populations from fertile donors.²⁰⁰ N-acetyl-α-glucosamine (α-GlcNAc) and α-mannose (αMan-BSA) may interact with the putative receptor for one protein of zona pellucida: ZP3 in human spermatozoa.^{195,202–205} This binding results in the exocytosis of the sperm acrosome (AR).²⁰⁶ The GlcNAc-BSA-induced acrosome reaction is inhibited by a small ligand: N-acetylglucosamine (GlcNAc) and by a purified soluble hydrolase, β-N-acetylglucosaminidase. The induction of the AR with Man-BSA was inhibited by mannose, while soluble α-mannosidase was only partially effective. These data suggest that binding sites for GlcNAc and Man seem to be involved in the induction of the AR in human sperm. The induction of AR in human spermatozoa by GlcNAc-BSA could be used to predict their fertilizing ability in vitro.²⁰⁵

The induction of the acrosome reaction by GlcNAc-BSA and Man-BSA has been shown to involve voltage-dependent Ca²⁺ channels and a Gi-like guanine regulatory protein.^203,207 The GlcNAc-BSA- or Man-BSA-induced AR was completely inhibited by preincubation of spermatozoa with calcium antagonists, indicating a link between the binding of sugar residues of the neoglycoproteins and channel activation. The pretreatment of spermatozoa with Pertussis toxin (PTx) inhibits GlcNAc-BSA- or Man-BSA-induced AR, whereas cholera toxin has no effect. Therefore, the transduction mechanism for GlcNAc-BSA- and Man-BSA-induced AR involves G-proteins of the inhibitory type (GI).²⁰⁴

The effect of ‘peritoneal fluid’ on the human sperm acrosome reaction (AR) was tested.²⁰⁸ When the AR was induced by GlcNAc-BSA, pre-incubation with peritoneal fluid reduced (60%) the percentage of AR, while peritoneal fluid from either the endometriosis group or infertile patients without endometriosis caused no significant differences. These data indicated that peritoneal fluid possesses a protective factor which prevents premature AR.

Cell Loading and Sedimentation